Panic is very similar indeed to the ladders-type arcade game. An almost identical version is now available for the BBC Model B under the name Monsters. Though Panic may not be 100% original as a game, it is very well written indeed.
The idea is that you are caught in a maze of walls and ladders with a load of rather nasty aliens. The object is to lure them into holes which you have dug and then bang them over the head until they die. As if this wasn't enough you are in danger of running out of oxygen. As time goes on, and especially if an alien gets through a hole without getting hit, they get even more ferocious and difficult to kill.
Maybe not original, but this is the first time I have seen it for the Spectrum. It is definitely a highly addictive and enjoyable game to play.