Spelunky is a perfect game. But, even though HD is amazing as can be, Spelunky 2 reinvents the word 'perfect'. They amped the difficulty up, and I never have beaten HD Olmec or have even looked at King Kool Aid. I used shortcuts to beat Tiamat, though, and I lucked out on the yetis having a freeze gun. They added so much more content from the first, and new areas! You can even get classic Spelunky Guy but why the hell would I spend 90 minutes on a CO run to get stars! Branching paths! More nitty gritty details! And to top it all off... you can pet Monty.
It is designed to torture you. 10/10.