Research

Doing some research on the net and came across a few games. Chasm is a good puzzle Flash game by Transience. They also do one called El Emigrante that is quite a laugh, although the movieclip is better than the game.
These weren't heading in a particular direction so decided to go back to what I knew, some the arcade games from my younger years. Defender, and a similar game called Stargate (nothing to do with the Egyptian Sci-Fi one), and Asteroids were favourites and seemed simple enough, but engaging, and also 2-D. I thought they would be good contenders.
'80s Music Lyrics has a few popular arcade games from the 80's re-engineered in Flash. Tried out Moon Patrol and Asteroids.
A really like the Vector graphics style video games, and the eerie CRT phosphorescent glow the lines used to have. So Sci-Fi and so laser like! Simple and striking! Bring it on!
Really liked the Asteroids one, but since it has already been done, decided to skip it.

Decided to go really far, back with some Commodore 64 Games from the 80's. For some reason two games (apart from Elite) stuck in my mind: Castles of Dr Creep and Paradroid.
Castles of Dr Creep is where you have to run around getting keys to unlock rooms, but there are traps, puzzles, and zombies thwarting your attempts. It's actually quite tricky (and a bit fustrating if you don't have much patience) and has a lot of switches and things that only work in a certain sequence. Tending to veer away from that one, as the gameplay is a bit slow and the programming may be too complex.

The one I did really like was Paradroid. The premise is that a transport full of robots travelling through an asteroid belt have been exposed to a radionic beam making them hyperactive. They have gone AWOL and taken over the ship and attacked the crew. (You don't actually see any humans during gameplay, so they must of all been killed).
Basically you have to clear the ship of the psycho robots. You can either do this by shooting them, or taking them over. You yourself are an Influencing Device Robot 001 (their highest goes to 999) so your guns are quite weak (especially against the more advanced robots) so the rule is generally to taken them over, jumping from robot to robot (they die when you leave them) up the robot tech tree. Unfortunately you can only take them over for a short peroid of time (the higher up the tech tree, the stronger they are, so the less time you can control them).