Why a mini pc? If you're after a cheaper PC, I highly advise buying a used one, like off eBay. There's very, very capable machines on there for like $200-300 with fuckimg RTX 3080's in them, from people who got into PC gaming during the pandemic that decided they don't have time for it anymore, or from cryptobros dumping old graphica cards now that crypto crashed, or from the steady stream of rich assholes who build a new PC for every generation of GPU and sell the old one.

If it must be a mini PC, you should expect about laptop level performance. They generally use laptop components and draw comparatively less power as a result. They're fine for office work and saving space, and you can get one that plays modem games, but you won't be getting a great value for the money in terms of game performance.

I usually would reserve a mini PC like that for HTPC use, running Kodi and serving up pirated content including emulated games and anything similarly modest, with newer games being more of a bonus.