[PC, Steam] Free: Jazz Lightning : Castle Dungeons (Was $3.69) @ Steam

The game is now free to play.

Jazz Lightning : Castle Dungeons is a single player pixel 2D action platformer where you need to find your way through lethal castle dungeons and obtain their mythical gems. In order to do that,our hero needs to avoid various traps, jump over dangerous pits of poison, dodge sharp spikes and find the lost silver key to unlock the door for the next room of the dungeon.
Inspired by the old classic retro horizontal scrolling platformers.

Only 10 reviews but positive. Not sure why its not so popular.

Credit to Hiphopopotamus at OzBargain