M.U.G.E.N

Similar to Osu!, it's hard to rate a game like this since it feels similar to rating its community. Nonetheless, considering an average MUGEN setup, this is still decent at best.

The most enjoyment I've had from this game was watching AIs go at it. One thing to learn is that AIs will probably play the game far better than you ever will, depending on characters. There is no way to ever play a character like Dark Donald as well as the AI does (most likely, anyway. it requires insane practice I'd imagine if you do)

There's no real way to learn the game. There's standard fighting game buttons, but overall the only way to learn the game is if authors provided move lists with their characters (a lot of them don't) or the community does it for you (still, a lot of them don't). Nonetheless, it's still fun to just let the AIs duke it out.

The best way to see how this game looks I'd imagine is through SaltyBet. It's a virtual gambling site (no real money involved) that sets up dogfights amongst characters via their AIs, and it has automatic tournaments and matches setup, along with viewer-created matches.

Things like SaltyBet really exercise the fact that this game is an engine at heart, and not so much a game. At its core, it is merely that.

From characters that are made for hentai, made for memes, and made out of MS Paint with the worst AI in the world; MUGEN's community creates some of the most batshit insane things I've ever really seen. Name a fighting game where Barney can go up against Tiger Woods and Ronald McDonald and come out a victor.

A gem of the past, to say the least.