You should definitely give Binding of Isaac a try.
Here's a link to the game: https://store.steampowered.com/app/250900/The_Binding_of_Isaac_Rebirth/
Binding of Isaac is a roguelike replay-value singleplayer game.
At start, the game might be a little hard, simply because you don't know what to expect. The map is RNG, enemies are really different, bosses are hard, and the game gets progressively harder. You'll get the hang of it. It's really addicting, really worth a shot :p
And what makes the game so awesome, is the different item synergy. For example if you get a laser beam item(Called Brimstone) and a quad shot+triple tear shot, your laser beam would look something like this http://i.imgur.com/T7xkYLx.jpg
Here's what it looks like normally