Invader Alien Base is a game in which you need to capture a base which is full of enemies. These include robots, as well as many monsters in the dungeons. Some basements are destroyed, so climb up the level to other bases by taking off.
You must be diligent and take them out one at a time, and this is no easy task.
Control keys:
WASD - Character Movement
SPACEBAR - Jump
SHIFT - Sprint
1,2,3,4,5 ...- Weapon change
K - Gun illumination
R - Reload
V - Change shooting mode
Esc - Exit menu
LMB - Shoot
RMB - Aim