Fairly decent Tiny Toons game that Treasure developed. The same engine built for this game was used for Astro Boy Omega Factor from what I've heard and could tell.

The game does kick your ass into next week if you try to approach it like any other beat em up, which makes me easily see why folks probs wouldn't enjoy it much. However, once you get into the groove with stringing a bunch of enemies into each other, chaining them into your specials, and using the other characters as MvC style assists, it all comes together to create something addicting.

It's a pretty short game, but with the difficulty in mind, you might take a bit. There's difficulty options and unlimited continues though so its still pretty doable. Music is solid and visuals are really damn nice.