The fan-made Undertale vs Homestuck Platform Fighter
Made to be Modded
The game is built with modding in mind! Not only do you have open source access to the entire rust source code. But the game also has powerful built-in tools, allowing you to create your own characters and stages without writing a single line of code.
You can download the latest build here. Currently you need a gamecube to wii u adapter or an xbox controller to play.