This is why I love retro compilations. Ristar is exactly the sort of game that I'd never play otherwise. It's one of those games I vaguely remember existing when I was a kid, but had a cutesy mascot who we never saw again and I'd have no real reason to seek out on my own. But because it exists within a compilation that I own, when I recently read something mentioning it I was like "oh hey, I already own that game. I should play it."
I did actually play Ristar once in the past - same deal. It was on a compilation. A console compilation. But this time I was playing it on Switch in handheld mode and really, these sorts of games are perfect for that. To paint the picture: it was bedtime for baby. So I was playing in a darkened room with the volume real low, relaxing before bed.
I wouldn't call Ristar a great game, but I'd definitely call it an interesting one. Developed by Team Sonic and published between the onslaught of their 16-bit Sonic games but before Nights Into Dreams on the Saturn, this game totally feels like a missing link between those two things. The game has a very 'Greenhill' look to it with those lush greens and bright blue sky. Ristar himself (who's some kind of walking... star?) plays a BIT like Knuckles since he's kind of grabby and can do some wall stuff. And in swimming levels the controls are reminiscent of Nights Into Dreams. It's kind of neat to see that evolution.
The main gimmick of Ristar is his arms. He can grab stuff. So he grabs enemies; he grabs branches of trees above him; he grabs onto bars and can swing himself around them. It's not always the most intuitive playstyle, but it's cool to see Team Sonic trying some different things instead of what's just tried and true (see: Sonic).
Some of the level design is definitely fun, such as the early overtly Greenhill style stages. Some of them are pretty annoying like the later music-themed ones. It definitely feels like a "let's see what sinks and what floats" kind of game. For me the real joy is in the boss battles which often feel like puzzles built around the grab mechanic.
Like I said, it's not a great game. And as short as it is, I tend to tire of it pretty quickly. But from a purely historical standpoint, it's definitely a game worth checking out if you're a fan of Team Sonic.