Have You Played? is an endless stream of game recommendations. One a day, every day of the year, perhaps for all time.
I know the cause of every single one of my thousands of deaths in Spelunky. I died down that snake pit because I frittered away my bombs and ropes, leaving me with no way to escape. I died to that inanimate rock because I drifted down towards it with the jetpack when it was being propelled into the air by a jump pad. I died to that blue frog because I overestimated the extent of its jump.
I died because I am not good enough at negotiating the roguelike platformer's strict rules. Not yet.
Those rules are really something. Everything about Spelunky's procedurally generated world is predictable, from enemy movements to trap speeds. The trick to mastering progression through the game is in closing the gap between your ability to mentally simulate what's about to happen and your ability to execute whatever plan you come up with. The plan: drop down on that spike trap, jump and whip that bat, hop on the head of the caveman. The reality: drop down on that spike trap, take damage from the bat, fall in front of the spike trap, be one-hit-killed by the spike trap. Try again.
The proc gen means that each new death is varied, but also exciting. Playthroughs where you find a free jetpack on an early level feel completely different to those in which you scrape by with few resources. But it's those rigid, predictable rules that make me keep coming back, to learn something new or to master something previously learned.
The free version is still good too.