

Idle Slayer has held my attention for a few years now. It’s cross-save and free on steam. It’s got interesting progression and non-predatory micro transactions. Although, I would say it might be a bit too active for what you’re looking for. Might be worth a try though.
Melvor Idle seems cool but I haven’t put much time into it. It’s made by jaggex and it’s essentially idle runescape except it’s all done in numbers and progress bars. I.e. you set ur guy to train fishing and they just fish, gathering materials and xp until you come back and set it to some other task.
If Melvor is “idle runescape,” then ‘Idle MMO’ is “idle maplestory.” I played idle mmo for a bit but it’s definitely a lot more attention demanding than anything else I’ve mentioned here so it’s probably not what you’re looking for.
Of course you can’t go wrong with any of the basic cookie clicker-types like AdVenture Capitalist, Egg inc, etc. Although if you’re looking to only play on pc I would suggest you just go for the OG cookie clicker.
good point I haven’t played that one since it was on miniclip