Summary
Platformer 2D turns Minecraft into a side‑on 2D world with custom Nether/End portals, caves, darkness/terrain rules, and gameplay tweaks designed for this new style.

Description
Platformer 2D is a full 2D overhaul for Minecraft 1.21.8 (NeoForge). The entire experience is constrained to the z=0 plane, so exploration, combat, structures, and traversal are all designed for a side‑on world.

I highly recommend that you disable damage tilt by going to Options > Accessibility Settings > set Damage Tilt = 0%

What this mod changes and adds:

2D world slice: The game is restricted to z=0, with movement, targeting, and entity behavior tuned for a side view.

Custom cave systems: Multiple 2D cave styles (bands, worm tunnels, pockets, chambers, terraces, rivers, and branching patterns) carved specifically for the slice.
Darkness layers: Underground blocks transition to darker materials based on distance from exposure.

Custom Nether portal: A new Nether portal design ideal for 2D (requires exactly 10 obsidian)

Custom End portal: A new end portal layout designed for the 2D plane. Craft 6 end portal frames and refer to the image for the proper layout. Then place an eye of ender in each end portal frame. You can build the end portal anywhere.

Gameplay adjustments for the slice: Targeting, interactions, and entity positioning are tuned so combat and exploration work cleanly in 2D.
Increased mob spawn rate: Night is much more dangerous
Blaze spawner rooms: New Nether structures to make finding Blazes easier
EnderDragon behavior: Beds no longer kill the Ender Dragon, and he charges at the player frequently so be prepared! Only 2 end crystals need to be destroyed, but this ender dragon is more deadly.
New Controls: 'A' moves you left, 'D' moves you right, 'W' is to sprint, and 'S' is to walk backwards.
Multiplayer is supported if you use the Essential Mod.

This is not a fork of another mod; it is a standalone 2D conversion with new worldgen, portal behavior, and gameplay rules designed for a side‑scrolling Minecraft experience.