Amazing. One of the best action-platformers I have played. It's also pretty much the first faux-retro-pixel-art indie platformer. It might look like a high end SNES game, but it's really just a plain PS1 game.
The difficulty also really reminds me of a modern indie game. It's really hard, but with a lot of check points. Like, Mega Man is just moderatly hard, but with few check points. It's like doing a sprint vs a marathon.
And I think Little Ralph's system is amazing. You get multiple check points per level and infinite continues, but you can't respawn at every check point after a game over.
E.g. this minecart section. You have to finish it in one continue, but you do get a couple of check points during it you can respawn at after dying, but not after a game over.
And it has one hit deaths. At least on normal difficulty. Easy is default and only gets you to level 5 of 9. I found myself challenged, but not frustrated.
The game also has multiple paths through a level, secret goodies and it's all a continues journey. No map or even a level screen. You just walk from one to the next.
Most annoying thing for me were some of the boss fights, because it would suddenly switch to a fighting game mode.
It's Japanese, but you don't need language for a platformer. Also available on Japanese PSN.