Metallic Child demo is a 3rd person melee action game where you play as a human controlling a mysterious space station battle robot: Rona

At first glance she appears to be an innocent child-like robot, but beneath the skin she packs-a-punch!
Use several skills and melee weapons to destroy enemy bots then combo them together and take out challenging bosses.

https://store.steampowered.com/app/1490610/METALLIC_CHILD/



The demo on steam is basically an introduction and tutorial to the game. Proton handles it just fine and I was able to play through the entire demo. Once you learn the basics, this is a fast moving action game with a lot of variety and upgrades.

Specs:
Mint 20.1 64-bit
GeForce GTX 1060
Nvidia 470
Proton 6.3-7