This one has an amazingly unoriginal theme. You control a space ship and your aim is to destroy attacking alien craft before they hit you.
But don't switch off just yet. The novelty here is that you're presented with a view from the cockpit and you actually see the alien ships getting bigger as they zoom towards you. Now that 3D is all the rage, Dimension Destructors isn't a bad effort. It takes a while to get used to, but you do eventually start to feel you're inside a space-craft. I found myself ducking once or twice when the attackers flew a bit close overhead.
However, the amount of memory needed to simulate 3D imposes considerable constraints. The attacking craft are simple line drawings and you don't get anything like the variety of attack waves possible in 2D games.
Verdict? It's different, but I think you could get bored with it fairly quickly.