(Click the picture for the steam page)

Super house of dead ninjas is a simple, arcade-style platformer where you're running down a tower full of enemies. The objective is to clear the three levels and defeat their bosses to be the ultimate ninja champion or something like that.
An important mechanic is the rage meter, it charges up when killing enemies without getting hit, and if it reaches full, you go invincible. The best thing about it is that you can keep the invincibility by continuing killing enemies. It's harder than it looks like though, you really have to to fast to keep it forma decent amount of time.

Not much more to say about it. It's pretty simple, but it's super fun, and for £1,75 i think it's a great time killer. There's also a dlc you can get for really cheap (£0,75 i think it was).
I'll just leave you with a gameplay video below, the player clearly has some warm feelings for the game.