Decent gameplay, but frustratingly difficult at times... virtually impossible to complete without a walkthrough
The gameplay in Rayman Advance is fairly typical for platformers, lots of jumping puzzles, killing bad guys, and avoiding obstacles. In most cases these are done quite well and really put your skills to the test. Most of the bad guys are reasonably challenging, though a few are pretty annoying to defeat. The gameplay varies as you progress so it never feels like you're just playing the same level again with different backgrounds.
Another nice touch is that if a boss is giving you too much trouble, eventually half of their hit points will be gone right from the start of battle making it a bit easier for the player.
One of my gripes is that some areas of the game are incredibly challenging and become more than just a test of reflexes, but more a test of memory. Things are flying by so fast that often times you don't realize there's a large spiky crystal blocking your path before its too late. This wouldn't be much of an issue if the game didn't restrict you to a limited number of lives (something which I hate in any platformer even some of the best out there like Super Mario Galaxy). I never lost all my continues (though I imagine that it would mean game over and you'd have to go back to the last save... frustrating since you lost any in-level checkpoints) but that's because I just used a 99-lives code... several times.
Another reason I was losing so many lives was from the hunt for electoon cages, many of which are well hidden and sometimes in places where you're not quite sure if its safe to jump down. I lost many lives jumping down to find them only to land in water or on spikes. What's worse, and this is my main gripe about the game, is that in order to actually fight the final boss and pass the game, the player needs to find every electoon cage in the game. That's 6 per level in all 17 levels... Some of the electoon cages are so well hidden that only the most hard-core gamers who want to spend hours just searching for cages and replaying levels over and over again will be able to find them all without a walkthrough. And for most of us who would need to resort to a walkthrough, it barely feels like its worth the trouble of trying to decipher someone else's description of where to find the cages you've missed.
I can only recommend this game to people who either don't care about passing a game, or those who are really in for hours upon hours of cage hunting. Unfortunately, I have to dock this game severely for the ridiculous requirement that you complete the game 100% in order to actually pass it.