Montezuma's Return is the sequel to the home computer classic, Montezuma's Revenge and let me tell you that this game is a hidden masterpiece that you are missing on.
It's a fantastic first person platformer, the worlds of the game are filled with hazards, the level design is simply fantastic and challenging. I really wish that there were more games like this one but first person platforming never really caught on beyond some niche titles like the Jumping Flash series and maybe Portal.
You are gonna need nGlide to play it and make sure to remap the keys since the default scheme used by the game is pretty dated and weird.