Heard a lot of people liking La Mulana..
How's it compare to Spelunky?
It's nothing like it. The only thing they got in common is that they both have platforming elements (Spelunky more than La-Mulana).
La Mulana is a metroidvania oriented towards puzzle and riddles resolution with a gigantic amount of content (20 to 30hrs depending on how much you use a guide). The game is also very hard and you will need to retry some boss battles a lot to get through them.
The platforming is stiff but you can do nice things with it when you master it.
The OST is boss :
http://www.youtube.com/watch?feature=player_embedded&v=-rfhi6I84hM
The riddles/puzzles get really tough to resolve once you hit approx. the middle of the game (Gate of Illusion) so there's no shame in using a guide when you get there to at least know where you should be going since the map is so fucking huge. There's also a few riddles that will make you say "that's bullshit and you know it" but it's part of the game (I'm talking Numb3rs levels of fuckedness here). It's still manageable to beat the game without a guide but it's five-months-old-baguette hard.
All in all, depending on how the game clicks with you it can range from being an obtuse and weird piece of software to one of the best/the best metroidvania ever made. One thing's for sure and it's quoted in the store page : we may never get another game like La-Mulana. (EDIT : this was before La-Mulana 2 was announced so you can guess I'm pretty happy)
