Pandemonia

It is the year 2000, and so of course aliens have invaded. They have decided to make their base in the CRL skyscraper, and it is your job to make your way to the top of the tower and destroy their control centre.

Pandemonia is a variant of the arcade game Space Panic. As is usual in games of this type, you are in a maze of floors connected by ladders. Aliens wander the area, and you can destroy them by digging holes in the floor, waiting for them to fall in, and then filling them afterwards so that the alien falls through the floor. A few of the stronger aliens need to fall two or three floors in order to die.

On the very first level, there are doors at the top of each of the ladders. Opening these doors reveals an alien, and activating the glowing door at the very top of the screen will open all of the remaining doors at once. Defeating all of the aliens on the screen will take you to the next level of the skyscraper. Subsequent levels still have wandering aliens, but do not have doors. All levels also have a time limit in the form of an oxygen gauge, which will result in the loss of a life when it becomes empty.