Cave Story was a solo project built during his off hours from a software job for a print company released as freeware in 2004. A second genius has created a walk-thru of the game composed as a rap over the game's (reproduced, resampled) background score. He explains here how he is giving it away for free via a google drive because #BandcampFriday doesn't support freeware. It's a delightful masterpiece.
https://www.reddit.com/r/cavestory/comments/1rqwokj/cave_story_a_lyrical_walkthrough/