AR-RIVAL: alien defense

Not many people know this, but ever since the first aliens landed in Roswell, they have been scouting earth. It seems that they are all around us. Most of us, haven't noticed, because they are using cloaking technology which makes them invisible to the human eye. However, with this app, it allows you to see them. It also enables you to destroy them, using a high tech lasercannon. Tap on the UFO to shoot it down. Beware though, once the aliens know that you are on to them, they will try to destroy your laser cannon... How many can you destroy, before your cannon is destroyed?