how are we sure it's not harmful? sry new to Itch.io
im pretty experienced in vns and whatnot as ive been playing for one to two years now, and to be honest, in these types of games there's no viruses at all. every game i've downloaded so far hasn't given me a virus. i play on windows and ofc antivirus has popped up a few times but i usually just go on with running it anyway. there isn't any definitive proof about whether there's a virus or not, but consider my words carefully.
hihi, a lot of games from itch.io will trigger the "do you trust this app?" warning from windows, i'm not entirely sure why, it's probably something to do with the formatting. if ur skeptical about a game being malware tho, you can check it here: https://www.virustotal.com/gui/home/upload or make a post asking about it in some subreddit or something. regardless itch itself checks the game files for malware.
the "do you trust this app?" warning happens often, so i don't take it too seriously but if ur antivirus gets rid of the files u might want to be more careful. never happened to me so it means it's probably malware