Kops

Kops is a two-dimensional gravitational shoot-yer-friend game in 640x480x256 graphics mode. The original version was made back in 1996. This is port from the DOS version to Windows and released as freeware.

You control your ship with five keys; thrust (move forward), turn left, turn right, fire main gun and fire special gun. Both main and special guns can be upgraded by picking up power-ups that appear around the level from time to time.

When you pick up a main gun power-up, your gun is replaced instantiously. Your main gun also has unlimited ammo. If you pick up worse gun than you already had, tough luck.

Your ship also has a special weapon with 2 to 16 slots; only one slot can be active at a time. To activate another slot, you must either visit a base and pick the slot, or pick up a next slot-power-up. The special weapons have limited ammo.

When you visit a base, your ship is also automatically repaired; this takes time, and you are literally a sitting duck when you are being repaired. You also must return to a base when the last enemy goes down. The bases may also be destroyed along with all the other terrain, but they regenerate in time.