Last, there's Crystal Quest from Pocket Money Software. This is a 100 location Quilled text adventure set in the world of Star Trek. The Earth is in serious danger and you must pilot your space craft where no man has gone before to find the three Crystals which will save the human race.
At the start you find yourself in the overheating engine room of the ship. The warp drive is due to malfunction so you have to race to the control room and warp out of Earth base, pronto. There are steering systems to be mastered - if you get your colour coding wrong you could be in dead trouble and end up in a completely wrong destination.
Once you have learned how to steer the ship, you will find a variety of planets to explore - some with hostile alien life and some with robotic systems to contend with. You can use a transporter beam to get down to those landfalls but remember to set the coordinates before you beam down.
Trekkies will like the game as will anyone who can only afford a small amount of cash to buy their software. At 99 pence the program is terrific value for money, and compares very favourably with a lot of games costing five times as much. Beam me up Scotty!