It's based on our hit game '8 bit Doves' which is level based and not free. If you like this there's a good chance you will like that too so skip coffee one day and buy that instead!
You play with only two buttons which means they are big and easy to hit with your thumbs. But then it's one of those super hard 'argh I hate this... but must have one more go' type of games too so yeah.
That's about it. If you read this far you may as well hit the download button. enjoy :) or don't... it's free so you can always delete it again.