If you still want an estimate you can check on Steam Spy. Source: about 1 year ago

I think Valve will shut it down once it learns about the monetization. AFAIK that is what happened to https://steamspy.com/ when they introduced paid subscription tier. - Source: Hacker News / over 1 year ago

If you still want to see numbers, you can try with Steam Spy with VN available on steam. Most of the developers say that those numbers are false. Source: over 1 year ago

Research popular game genres, for example on https://steamspy.com, and find a genre that currently sells well. Source: almost 2 years ago

Steam Spy - must have tool for anyone who wants to get some data about Steam games. Source: almost 2 years 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: over 2 years ago

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