Alter Ego is an NES homebrew port of a ZX Spectrum puzzle game of the same name. You control a character who can switch places with his shadow a limited number of times in each stage. The goal is to collect all the items without touching any enemies. To further complicate matters, the blue-outlined items can only be collected by the shadow, whereas the pink-outlined items can only be collected by the main player.
This hardly stops MESHUGGAH, though, who barely avoids death in a number of puzzles and finishes in record time.