

The alien levels share some similarities with the alien converted floors, however the major difference is that no kill percentage is required to move on an exit teleporter must be found instead. The CD version features 10 more levels: rather than destroying the Vortex, the player walks through it to reach the aliens' homeworld. This version of Corridor 7 ends when the player destroys the Vortex on level 30. The total of these 36 levels makes up the original floppy disk release of the game. Such elevator is usually guarded by an alien boss. A third section is made up by the six bonus levels accessible on specific levels throughout Delta Base using an alternate elevator. The converted floors feature a darker light setting and the almost complete disappearance of human made equipment. Next comes the so-called alien converted floors: these 10 levels of Delta Base have been completely reorganized by the aliens who brought in their own devices and structures. The first twenty levels of Delta Base comprise a mix of offices, research labs, computer rooms and storage warehouses themed with appropriate decorations and furniture. On the corporal difficulty the full map is shown with no need to collect the floor plan.Ĭorridor 7 levels can be split into different blocks depending on their setting.

Upon collecting this object the proximity map is extended to show the whole level and the position of every alien. This function shows a small section of the current level with all active aliens as yellow blips and can be expanded by finding the floor plan.

To help hunting down the aliens the player can activate the proximity map in one corner of the screen. There are four skill settings available without manual input in the floppy disc version, which influences the percentage of aliens that need to be eliminated, and a fifth setting that is immediately available in the CD version which randomly scatters enemies and items throughout the game. The gameplay slightly differs from that of most FPS games because the player, rather than finding an exit surviving the various enemies scattered around, is tasked with the duty of killing the aliens present on the level once this objective is achieved he will be granted access to the next floor of the base through the lift by which he came at the starting point of each level. Instead, there are 30 (floppy disk version) or 40 (CD version) levels to explore plus 6 more bonus levels. Like all first-person shooters, the game is rendered from the player's perspective. The player takes control of the lone soldier who has infiltrated the alien invaded military base.
