Ikemen Go strives to be compatible with Mugen, so anything Mugen can run should ideally be also playable in Ikemen Go.

You can download Ikemen Go nightly build (https://github.com/ikemen-engine/Ikemen-GO/releases/tag/nightly) and and try to run any Mugen game using Ikemen. Some things you need to do is extract Ikemen Go into the game directory and set a correct path to the system.def file in configuration.

Once You get the game to at least run, if there are still any incompatibilities with Mugen, then you can report them here: https://github.com/ikemen-engine/Ikemen-GO/issues and there is a chance that any shuch issues will be fixed in the future.