This is a collection of short games featuring Kirby, a pink balloon creature with the uncanny ability to copy enemy abilities and create allies out of them. The most famous are probably the platformers because I never hear people talk about the gourmet race or great cave offensive.
This has to be the easiest mainstream Nintendo platformer by a large margin, Kirby has a large health pool, healing items are abundant, enemies double as power-ups, continues are infinite, and the ability to float makes bottomless pits a non issue. If you can't beat this game then you are gonna have a lot of difficulty beating other platformers from the era.
I think the game has a pleasant tone about it and clearly a great deal of attention was given to characters and animations. Kirby in particular is really expressive and it's hard to not get attached to the pink protagonist.
The presentation is good in other areas as well. Some environments and enemies are shared within games, but the experience as a whole doesn't feel repetitive. I really like the main theme as well, it's really catchy.
To conclude, I don't think I've said anything that hasn't been said before about Kirby Super Star. It's a fun game with a cute, likable protagonist that doesn't take itself even remotely seriously. Neat.