Dungeon Crawler Carl

Aliens have come along, demolished Earth, and let a couple million of the remaining humans participate in a televised fight to the death for the rest of the universe to enjoy.

It's obviously an absurd situation, but the main character Carl is quite aware of the fact that a) most of Earth has died and b) more are dying every day. He also has a talking cat named Princess Donut.

So it's kind of this mix between humour and the depressing reality of it all? Good if you're looking for a fast-paced action book with a twist.