Although i'm a Roblox Youtuber, there are two games that i'm really hooked on during the pandemic. I've been getting into Nuclear Throne and Enter The Gungeon and they are huge timewasters. Both games have classes, and are a real challenge especially if you're looping the throne in Nuclear Throne. The bosses are also challenging, and both games ensure that there's never a dull moment.
Also in Enter The Gungeon, if you play as the hunter class you can pet the dog. The two classes that i would suggest starting off with in ETG would be The Marine and The Hunter. The pilot is a class for more advanced gungeoneers since he is more RNG based and relies on luck to get by . The pilot also has the weakest starter weapon in the game and has awful accuracy, making him really inefficient. For Nuclear Throne, the two classes that are great for beginners are Plant and Crystal. Crystal has the ability to shield and has more max health, meanwhile Plant is more speedier and can stop enemies in their tracks with the snare ability. Would highly recommend checking these games out, totally worth your 8-16 bucks.
Minecraft
I have a whole gallery of steam games, yet Minecraft is the only game I'm playing at the moment (other than pokemon go and jurassic world alive)
I've been playing that game since i was 10. Me and my sister have been building a custom minecraft server complete with a town, and a nice river for fishing. It brings back so many memories..