If you think about the low playtime - I've completed the game over 50 times on an Android device, getting every achievement. Can't transfer progress from tablet to PC though.
Chicken Invaders is a series of shoot 'em up video games, you control a ship which needs to save the universe from the Chickens - Which had enough of you eating them all the time.
While you play, you find a lot of different weapons, there's a weapon Level system too, when you defeat chickens, they sometimes drop a gift or energy orb - Getting the gift gives you a particular weapon, the orb raises your weapon level by +1. The amount of weapons is massive, one is a railgun, another one is a electroshocker, and each one can be either good for particular enemies/bosses, or bad.
You don't switch weapons while you play, when you find a box, you can get it, and it replaces your current weapon. You can't switch back to it until you find another box with that weapon you want.
Each wave is completely different, in one you see chickens moving in a clockwise way, in a different one they will be in shields which you need to destroy - every single wave is different.
The storyline, it's really good and hilarious.
Soundtrack - It's beautiful.
In other words, if you like space shooters, get this. It's not too hard, it's not too easy (Well there are 3 different difficulity levels) You'll very likely enjoy this game. I've been playing the series since I was a young kid, and I still love it. I'm even beta testing Chicken Invaders 5 now, because I want to help the game series, because it's simply amazing.
It's a space shooter for 5 bucks.