Impact is a game by Bob Smith for the Sinclair ZX81 and his interpretation of Atari’s 1979 arcade game ‘Asteroids’.
This is what Bob had to say about the game:
“One of the reasons I turned my attention to the ZX81 was the lack of good games for it, and by that I mean graphically rich, fluid, and responsive games. One of the games which I felt was furthest from being this on the Zeddy was Asteroids, as the versions of it released at the time were largely slow, unresponsive, and difficult to play (I mean, having your ship displayed by the digits 1 to 8 depending on which direction it was facing? Really?!)
So, I decided to write Impact! as my interpretation of the game – featuring smooth movement, fluid gameplay, player inertia (always loved rotating, thrusting, and firing all at the same time), and graphics which actually look something like the original arcade. It is missing the enemy saucers which appeared in the arcade version, but given the smaller playing field (the 64 * 46 effective pixels) I don’t think that is a huge loss as the game is frantic enough without them.”