You have constructed a vehicle in which to visit the outer layers of the Celestial Oversphere and do battle with those who sit in judgment of the Universe.

On each layer of the Oversphere you must fight your way through hundreds of enemies.

Most of the foes you meet must be destroyed for you to reach the next layer. A secret ritual has shut the fearsome Eyes of the Watchful Ones, although only for a time.

You will have from two to three minutes in each layer before they open again.

You can tell which enemies you need to destroy by looking at your overview on the bottom right of the screen.

Essential targets are large yellow dots, while unimportant ones are small and orange.

The amount of time you have, and your progress through the layer, are indicated on the top left of the screen, while on the bottom left you can check how well your vehicle is holding up against the fury of your enemies and how many lives you have.

If the normal game isn't frantic enough for you, go to the Special menu and choose Time Attack mode, where the goal is to survive for as long as possible, and every essential target you destroy gets you a few extra seconds.

The Special menu also includes Duel Mode, which lets two players fight it out between them, although the game isn't very well-balanced for this. Below Duel Mode are some challenge mode settings which you have to unlock by playing the main game. They make things even more difficult.