Whatever platform/engine(s) you end up trying, you both might enjoy looking through the game assets that Kenney shares with the world for free: * https://kenney.nl/assets * https://kenney.nl/starter-kits The asset range includes 2D & 3D and in a variety of graphical fidelity/style from 1-bit to low-poly--including sets which are designed to work together. The "Starter Kits" are a more recent development which aim... - Source: Hacker News / 4 months ago

These look fabulous. Another great resource for free 2D game assets: https://kenney.nl/assets. - Source: Hacker News / 5 months ago

Look at kenney.nl/assets, hundreds of sounds and other assets, all free. Source: 12 months ago

Most of the assets came from Kenney, but there are way too many combined sources to list them all here. If you want to know where anything came from, feel free to ask. Source: 12 months ago

Not quite an answer to the question, but there's a bunch of free asset libraries out there! Assets · Kenney. Source: about 1 year ago

I recall this obscure yet fun game with simplistic graphics. It looked a lot like Crimsonland, but as far as I know, it had a campaign mode with bosses. The things I recall most vividly were skill trees with the respective playable character in the background, as well as a character that had dual miniguns(?) I used to get many games from the then-popular site caiman.us, so it might've been from there, but I'm... Source: about 2 years ago

Probably not as it's not (and never was) all black but http://caiman.us/ ? Source: almost 3 years ago