Xcel

In a period of advanced technology, humanity created 30 Sentinel planets –
advanced technological devices that were designed to protect us forever.
Inevitably these rebel, and destroy everything in their path. Some years
later, with society having declined, they must be destroyed, and this is where
you come in.

Gameplay has several elements, with the first task being to locate a Sentinel
and guide your ship to it. Two inbuilt computers can be used to help you with
this. Next you must land on the planet’s surface, avoiding contact with
anything as you head for the ground.

The main bulk of the game sees you walk around the planet’s surface,
destroying all the alien craft you can find. These include dark creatures such
as Tri-Syncs and Mirobs.