Thunderstrike

Thunderstrike is a 3d spaceship shooter set in the year 2238, using a non-textured polygon graphics engine. As a pilot in the "Ground Defense Games", you must make your way through several arenas built on different planets. You can choose from four different ships, each with different properties (better/worse acceleration, top speed, or turning speed).

When you enter the arena, you are given several pyramids that you must defend from robotic drones sent out to collapse them. In addition to defending your pyramids, you must destroy the spawning centers that spawn not only drones, but an array of robotic fighters to hunt you down.

When you destroy a fighter, sometimes it will leave behind an upgrade pod (shield, turbo, power, or twin-fire). There are also tracks that you can latch your ship onto to travel the perimeter of the arena quickly.

At the end of each round, your performance is reviewed, and if you did good, your ship is upgraded and you move on to the next round.