Alien Shooter

Alien shooter takes you on a killing frenzy against a horde of vicious
creatures through ten huge levels. Armed with your weapon of choice, you
guide your hero around a secret military base, blasting enemies and
collecting power-ups as you go.

At the beginning of each level you can buy new upgrades for your
character with money taken from previous levels. Throughout the levels
you will be able to find ways of interacting with your environment, such
as shooting gas canisters to blow open locked doors. You can also use
gun turrets and other stationed weaponry you find to attack your
enemies.

As well as the Campaign Mode, there is also Survival Mode in which you
have to hold out for as long as possible against an oncoming flood of
alien invaders

As games go, Alien Shooter is pretty simple, but this can actually be
considered an advantage as if you like zapping aliens. Unfortunately,
you only get a very small portion of free play time before you have to
stump up £20 for the full version.