"Maelstrom is a 1992 clone of Asteroids with an improved graphics and interface. Many of Ambrosia's subsequent shareware titles followed in a similar formula.
It was created using THINK C and uses 18,000 lines of C code with 9,000 lines of inline assembler.
Maelstrom is played as a 2D overview in a section of space. The object of the game is to reach the highest score possible by shooting asteroids with a plasma cannon from a spaceship that the player controls. The ship can move in any direction across the screen and also has a limited amount of shield. The player may also pick up powerups throughout the levels or "waves" and encounter unusual objects and enemies throughout the game."
Source: Wikipedia, "Maelstrom (1992 video game)", available under the CC-BY-SA License.