Defcon 5

Just after uploading the automating code, the base is suddenly invaded by unknown assailants from the air and ground.

You must rely on your wits and the defence software to fend them off.

The main game takes place in a first-person view inside the complex.

Trams connect the maze-like living areas to a handful of manned turrets outside.

You must shuttle between shooting down waves of fighters in the turrets, and scouring the base levels for card keys during the downtime.

A third consideration is the "Virtual Operating System" controlling all major base functions.

You use this interface to repair damage from attacks, monitor intruders, and place robot sentries to guard key passages.

As you find more access keys, you can increase the software's efficiency to the point that you can command turrets remotely, or set them to auto-attack with a high degree of success.

As defending the base becomes more automated and efficient, you have more time to search the levels for keys.

Your ultimate goal is to find the clearance to self-destruct the base, defend your escape shuttle, and get out alive.

Defcon 5 for PlayStation is currently worth €17.96 loose, €14.47 complete in box, and €37.62 factory sealed. Prices are based on real sales and update regularly on Gamevaro.

Defcon 5 has a steady sales history on the tracked marketplaces, meaning it trades hands regularly and isn't considered particularly rare.

Loose means cartridge or disc only, CIB (complete in box) includes the original box and manual, and sealed means factory-sealed and never opened. For Defcon 5, loose is €17.96 and CIB is €14.47 — CIB commands a premium because original boxes and manuals are fragile and often don't survive.

The PAL version of Defcon 5 is currently worth €17.96 loose, versus €18.45 for NTSC-U. Regional price differences usually come down to print run size and regional collector demand.