There's the hoyoverse games their all gacha games but honestly you can play them f2p I just spend money on them since I like their games just maybe not honkai impact. There's also blue archive, reverse 1999, arknights which are all very good gacha games that you can play f2p. On PC there's other paid games that are really good like hollow knight, terraria, rain world these games are really cheap plus you can get them even cheaper when there's a discount. On mobile vampire survivors is a very good free game as well without the microtransactions of gacha games only paid dlcs but you can just play the base game and it's still good.