AVENGING SPIRIT / Jaleco / Gameboy
Avenging Spirit is apparently a port of some obscure arcade game called Phantasm. In a surprisingly grim intro, main character gets gunned down by random mustachioed gangsters and his girlfriend gets kidnapped. Turns out his girl's dad was into some heavy paranormal research and the Mob wants it for themselves. But he's summoned your spirit to give you his possession powers instead, allowing you to take over the bodies of enemies.
It's a fairly standard platformer, except you hop from enemy body to enemy body to get around. You've got a "spirit energy" bar that ticks away as you float around without a body, and when that runs out, the game is over. Each individual enemy also has their own life bar - usually not very long - and when that's exhausted you are back to floating around until you find another suitable possession subject. The enemy gangster mob is made up of a fascinating diversity of hitmen, ninjas, baseball players, missile-firing astronauts and many others, each with their own weapon types and movement speed.
It's also fairly standard for all the cheap bullshit level design of 1980s-early 90s platformers. Enemies constantly respawn when you go even slightly offscreen in Ninja Gaiden style, and in Shinobi style they also often like to appear literally in your face from out of nowhere, and are also always positioned in the most trollish position possible. The game is actually pretty easy for the first few stages and the bosses are easy throughout, but you'll slam into a wall of cheap hits in level 5 (out of 6) that it'll take some serious fortitude (or masochistic tendencies) to get by.
I dunno. It's a neat idea and pretty competently executed, at least at first, but toward the end it really stops being fun to play, and the music is godawfully annoying at some points. Plus, there's only six small and linear levels, so even if you endure the brutal last two, there's not a whole lot of play value here. Maybe the original arcade game is better?