I find that the idea behind Wario World is a good one, but the execution of the game itself was pretty poor, and could be improved in a lot of ways.

The secret stages are a cool idea, they're basically puzzle rooms where you have to use Wario's moveset to get to the goal and obtain the Red Diamonds, which are basically the equivalent of the Power Stars of Mario's games, the main problem they have is that there's a lot of them, and a lot of the time they just feel the same, but a bit harder.

The bosses themselves are actually one of the strongest points in the game, there's one per each stage, and an additional final boss, so for the game's length, it is packed with Boss Fights, the bosses themselves are also charming, with visuals similar to the ones of a comic book.

But sadly, this is everything I found worth praising about the game, the level design feels really repetitive, being mainly a item hunt most of the time, with a lot of combat sections, that are mainly mashing the attack button over and over again with no actual strategy, I think that the game would have improved a lot if some challenged from the Red Diamonds would have been part of the levels intead.

Then there's the fact that it's hard for Wario to lose all his health bar, but it's really easy to fall onto an endless pit, which doesn't translate to a Game Over, but brings you to a weird room where you have to find the exit, which is generated randomly. Those segments main purpose is to make you lose money, but money on this game is basically worthless apart from buying some recovery items, so in reality, those sections are only a time sink.

Overall, I think the game itself had the potential to be good, but there's a lot of weird decisions in its core design that only harm it.