If I had to narrow it to 10, it’d be this, keeping audience in mind.
- BattleBlock Theater $15 on Steam
- Broforce $15 on Steam
- Castle Crashers $15 on Steam
- Earth Defense Force 5 $60 on Steam (currently on sale for $15, ends Sept 1)
- Left 4 Dead 2 $10 on Steam
- Lovers in a Dangerous Spacetime $15 on Steam
- Portal $10 on Steam
- Rabbit and Steel $15 on Steam
- Stardew Valley $15 on Steam
- Wizard of Legend $16 on Steam