Don't Break the Glass!

Mum's gonna come home soon, and you have to kill all the aliens. Be careful though, if you break her glassware, she'll kill you!

The idea of the game is simple: Kill as many aliens as you can, while avoiding breaking any glassware. Sounds simple, but it's surprisingly hard to fend off the aliens while being very careful of the shots you make, and that one wont miss and hit any of the glassware behind it.