under 10 min speedrun or near that thank you :)

The original Super Mario Bros. is a short and sweet speedrun. It's worth a try. Unfortunately, we can't link to any ROM files directly because piracy isn't great, so you'll have to search yourself.

Pretty much the entire Game Boy library.

Note that with the GB, many emulators are banned for inaccuracy. But you will find bgb and gambatte legal on most all boards.

Consider mobile. Lots of free games and (contrary to popular belief) a lot of them are credible. If you want any recommendations then let me know what genres you like and whether you are on android or ios.

Or run webgames! There's plenty of great ones and they're free. If you're on desktop a lot then you can just open it up in your browser and play away.

Trackmania: Nations Forever is a free racing game, and if you work on White%, it will take you less than 10 minutes per run, with the WR being 5 minutes RTA.

Locking this because this is encouraging piracy.