A redesign of the Survival game mechanics that aims to provide a slower-paced experience with a focus on the sandbox and resource gathering aspects of the game, without the pressure to obtain certain items or complete certain tasks as soon as possible and without the progression from a tedious early game to a Creative-like end game. If you're the kind of player that prefers building, mining and exploring over grinding, minmaxing or automating the game away, this mod is for you. It's partly inspired by the old versions of the game, but attempts to combine the best of both worlds.

Requires Sinytra Connector and Forgified Fabric API on Forge

Underground pond

Detailed list of changes:

New items:

Bolster: Pickaxe and Shovel-like tool that behaves as if it had Silk Touch
Charged trident: created when a trident is thrown at a wool block, it's equivalent to a trident with the Channeling enchantment
Magnetic trident: equivalent to a Loyalty III trident, created when a lightning strikes a lightning rod
with a trident on it.
Piercing Arrow: Piercing V-like arrow, made from iron. They can be picked up and reused after hitting a mob.
Igniting Arrow: Flame-like arrow, made from fire charges.
Blazing Sword: Fire Aspect II sword, crafted from netherite and blaze powder, same attack strength as diamond.
Sacred Sword: Strong against undead mobs, sold by the wandering trader.
Golden Berries: Found in underground ponds or crafted from glow berries, they can be eaten quickly and give Instant Health II and Glowing.
Ancient Codex: Found in structures, can be sold to villagers and wandering traders.
Evil Totem: Dropped by mansion evokers, can be sold to clerics and wandering traders. When equipped in the offhand slot, it gives the Bad Omen effect and it becomes impossible to unequip it, unless a raid is started (1.20) or the effect is converted into Raid/Trial Omen (1.21), after which the totem is destroyed. Mobs are hurt when they attack a player with the totem equipped.
Terrible Potion: (Awkward Potion + Echo Shard) Base for the potions this mod adds.
Teleportation Potion: (Terrible Potion + Ender Pearl) Can teleport to a lodestone if the player is holding a compass pointing towards it. Mobs hit by the splash version of the potion will teleport together with the player that gave it to them (bosses are excluded). For convenience, you can give a name to a lodestone by right clicking it with a name tag.
Silence Potion: (Terrible Potion + Phantom Membrane) Prevents sculk sensors from being triggered. Has a long version.
Fatigue Potion: (Terrible Potion + Prismarine Shard) Gives Mining Fatigue. Has a long and a strong version.
Haste Potion: (Fatigue Potion + Lapis Lazuli) Gives Haste. Has a long and a strong version.
Locked Recovery Compass: This solves the problem of the death location being overwritten if you die while trying to recover your drops. When a recovery compass is used (right-click), the location it's currently pointing at is locked and subsequent deaths won't change it. There's only one possible locked death location for each player though; locking a recovery compass will overwrite the location of all the other previously locked ones. If the compass is locked by Shift + right-clicking, it will use the existing locked location instead of overwriting it (useful if you die yet again and lose the locked compass).

Disabled items: Totem of Undying, Enchanting Table, Grindstone, vanilla Enchanted Books (modded books are called "Item Upgrades" if the language is set to en_us).

Hunger:

The XP bar has been replaced with the stamina bar. It recovers passively based on the hunger level, consuming it. The color of the bar indicates the speed of regeneration.
Sprinting on most blocks quickly depletes stamina, much faster than it recharges, and so does swimming vertically. Sprinting on various artificial blocks (dirt path, planks, cobblestone, bricks, etc.) consumes less. This feature is controlled by the #unsteady block tag if steady_block_blacklist is set to true (default, recommended for modpacks), #steady otherwise.
Passive healing is always slow and depends on the stamina level, and doesn't consume stamina nor hunger. Use potions, golden berries or golden apples to heal quickly instead.
Damage from starvation is removed. Instead, the stamina bar recovers much slower when the hunger level is low.
Having portable containers with many items in your inventory also slows down your stamina regeneration. Donkeys and other entities that can transport items are not affected by this.
Sprinting, attacking or being hurt accumulates "weariness" which slows down stamina regeneration. The environment (underground, night, nether or end) temporarily amplifies weariness. Weariness is instantly reset after sleeping and skipping the night, and slowly resets over time if the player isn't doing much, especially if the player is riding a still entity (like a stationary boat or a modded chair).
The hunger level is depleted much more slowly if the player stays within a restricted area. The idea is that traveling long distances requires provisions, working on your base does not.
The maximum food stack size is 16 (with some configurable exceptions) and eating too much food in a short time reduces the amount of hunger replenished. This encourages eating nutritious food such as cooked meat over berries.

Combat:

Out of time attacks (faster than the weapon speed) are always at full-strength, but they're only allowed if there's enough stamina and they consume more of it compared to regular attacks. In time attacks are always allowed.
Shields consume stamina when blocking attacks. This makes out of time attacks harder to perform with a defensive style of combat.
Armor always behaves as if it had Protection II. Netherite and diamond also have better fire and blast resistance, and boots (leather in particular) protect against fall damage. Netherite has some extra wither resistance as well.
Crossbows behave as if they had Quick Shot II and bows behave as if they had Power III.
Potions stack up to 16 and last twice as long. The awkward potion can be made from the mundane potion using a fermented spider eye. If potions are brewed without fuel, each potion has a 10% chance of turning into a thick potion.
Tipped arrows can be crafted from regular potions.
Death drops are less spread out and can acquire fire resistance from the player that died.

World:

Mobs don't spawn above ground near beds that are active spawn points and have been slept into at least once. That applies to phantoms and patrols too.
Such special spawn points also work as backup spawn points that are used when the last bed/anchor is missing.
You can only sleep from 22:00 onwards.
Common structures (including the ones from mods and datapacks) are less common.
Zombies don't attack villagers.
Coal and emerald ores can generate anywhere underground.
Exposed diamond ores are more common, but there are less diamonds in general.
Prismarine patches generate above Y=0 in ocean biomes.
Large iron and copper veins are disabled.
Ancient Debris is much more common.
Blazes spawn in Nether Wastes.
Added underground ponds (see screenshot) at Y>0 with suspicious gravel containing golden berries and other useful items, most often generated intersecting a narrow cave.
When an underground pond is generated, a gravel or sand block on the surface might be replaced with suspicious gravel or sand.
Added underground cabins at Y<0. They always generate with a door to a cave wall, and they can contain various types of randomly generated rooms.
Added a small buried structure (northbound gate). It generates in a pattern similar to the stronghold, except that each ring only has 1 structure and there's an additional one that always generates close to the world origin. It contains a lodestone and many suspicious gravel/sand blocks.

Tools:

Tools are faster at mining. Gold is fast enough to instamine Deepslate when combined with Haste II.
Tools last twice as long, except for gold tools, which now have 200 uses.
The turtle shell gives 60 seconds of water breathing instead of 10.
Water breathing from any source also gives aqua affinity.
Lava buckets can only smelt one item.
The elytra can be crafted from phantom membranes.
Elytra gliding has a significantly lower maximum speed and firework rockets are also weaker when not flying vertically.
Repairing doesn't require XP and always consumes 1 ingot/gem. Renaming never damages the anvil either.
Netherite templates can be bartered with piglins.
Tridents can be repaired with diamonds.
Bundles, saddles and item tags are craftable.
Bundles can hold up to 4 stacks worth of items.

Loot:

Drowneds with trident always drop the trident.
Spiders drop more eyes.
Skeletons drop more arrows and occasionally feathers.
Zombies occasionally drop leather.
Wither skeletons have a 25% chance of dropping the skull.
Quartz ore drops more quartz.
End cities have less loot.
Ruined portal chests can contain blaze rods.
The Evoker never drops a Totem of Undying, and it drops an Evil Totem if it spawned in a mansion.
Mansion Evokers give the Bad Omen effect instead of Pillagers.
Ancient Codices can be found in various structures. More can be easily added to other loot tables from the config.
Assorted potions with positive effects can be added to loot tables from the config (many vanilla structures already have them in the default configuration).
(1.21) The rewards from the trial vaults have been changed. Most notably, regular vaults don't give ominous bottles anymore, while ominous vaults can give bottles of any level.

Trading:

The wandering trader spawns more frequently when the world is first created or if the players have been trading with it, and less frequently if it's killed by a player.
Wandering traders buy diamonds (for 1-3 emeralds), evil totems (64 e) and random ancient codices (32 e), and they sell various decorative blocks, healing potions, some tools (bundle, recovery compass, sacred sword) and mob drops (phantom membranes 4e, shulker shells 8e).
The wandering trader also buys the last renamed lodestone compass from each nearby player (excluding duplicates), and randomly resells them at a higher price. This is useful to get back to your base through teleportation if you died and your bed was destroyed but the lodestone is still there, and it's also useful in multiplayer to allow players to teleport to each other's bases without having to share compasses directly (players who don't want visitors can simply refrain from selling compasses to the trader). The trades are removed if their associated lodestone is destroyed, or if a player has sold over 30 unique compasses (the oldest compasses from that player are removed first in that case).
The armorer sells iron and chainmail armor, and iron and gold horse armor.
The butcher sells raw meat, feathers, hide and bone.
The cartographers sells compasses, lodestones, recovery compasses, ocean monument maps and mansion maps. It buys five ancient codices for 64 e (always the same ones).
The cleric sells glowstone, nether wart and potions with positive effects. Also buys evil totems (32 e).
The farmer sells crops, seeds and eggs.
The fisherman sells raw fish, buckets with fishes, ink sacs, glow ink sacs and nautilus shells.
The fletcher sells most types of arrows. Tipped arrows with positive effects are excluded (except Healing which is harmful to undead mobs).
The leatherworker sells colored leather armor, leather horse armor, saddles, item frames, glowing item frames and bundles. Buys phantom membranes (1 e).
The librarian sells regular books and buys nine ancient codices (64 e). The trades are dependent on the biome.
The mason sells bricks and polished stone blocks.
The shepherd sells strings and wool of all colors.
The toolsmith sells iron, gold and diamond tools, and chipped anvils. It also buys diamonds for 1 emerald.
The weaponsmith sells stone, iron, gold and diamond weapons, and shiels. I buys diamonds for 1 emerald.
Piglins barter netherite smithing templates (rarely). Soul Speed books have been removed and some trades weights and amounts have been changed

Summary of the enchantment replacements:

Available as a new item: Silk Touch (bolster), Smite IV (sacred sword), Loyalty III (magnetic trident), Channeling (charged trident), Fire Aspect II (blazing sword), Piercing V (piercing arrow), Flame (igniting arrow), Thorns (evil totem), Swift Sneak (the silence potion has a similar purpose)
Replaced by the stat rebalance: Protection II (all armor), Fire/Blast Protection (diamond and netherite armor), Feather Falling (all boots, leather better), Efficiency (all tools), Respiration (turtle helmet and other water breathing sources), Depth Strider (turtle helmet and other water breathing sources), Unbreaking (all tools), Power III (bow), Quick Charge (crossbow), Aqua Affinity (side effect of water breathing), Knockback (hit while sprinting and jumping upwards), Impaling V (tridents are strong against all underwater mobs, and also mobs exposed to rain), Lure III (fishing rod), Sweeping Edge (hit while moving the cursor fast horizontally), Soul Speed III (netherite boots have it without the durability penalty)
Removed by design: Infinity, Looting, Fortune, Mending, Sharpness, Riptide
Not currently available: Frost Walker, Luck of the Sea, Multishot, Punch, Bane of Arthropods
Available as random loot: Curse of Binding, Curse of Vanishing, modded enchantments

The configuration file unruffled.json allows you to configure many of the mod features and the trades. Recipes, loot tables and worldgen features can be configured with datapacks as usual (see here).

Optional features:

These features are disabled by default and can be activated from the config json:

force_reduced_debug_info_in_survival: If true, this makes it so that players in Survival mode can't see coordinates and various other debug info from the F3 menu even if the reducedDebugInfo game rule is set to false.
show_facing_when_force_reduce_debug: If the previous option is enabled, show the facing direction in F3.
show_biome_when_force_reduce_debug: Show the biome in F3 if force_reduced_debug_info_in_survival is enabled.
max_map_size: The maximum number of times a filled map item can be expanded. 4 is the vanilla default.
compass_points_north: Unbound compasses point north instead of spawn.
compass_points_north_toggle_spawn: If compass_point_north is enabled, allow to turn compasses into spawn compasses by right clicking them.

Unruffled