Jump on your jetbike in Lyn Davies' fast arcade adventure game and map an alien city

In this fast-paced machine code arcade game set in the distant future you take the role of intrepid space explorer Jim Bains. You arrive at a previously undiscovered planet in a far off solar system desperately short of fuel. Fortunately, you discover an ancient, deserted alien city and decide to explore it in the hope of finding fuel.

You don your spacesuit, climb aboard your jetbike and swoop down to the heart of the city. Luckily, scattered around are valuable fuel cannisters - which must be collected in order to refuel your ship.

Teleports are handy for moving between the different buildings, but take care, as it is very easy to lose your way. Robots - fortunately, no longer active - block the way in several locations. They can be disintegrated by running into them after first collecting a power pod.

Take care you can only carry one power pod at a time. If you try to pick up a second one it will explode, ending one of your three lives.

All the action takes place in a window in the centre of the screen which shows a small portion of the current location. You can fly left and right using the Z and X keys. The teleports - represented by an arrow-shaped object - are activated by flying past while holding down the * and ? keys.

There are several blind alleys from which there is no escape. If you end up in one press the B key to be transported back to the beginning. You will, however, lose one of your three lives.

The number of fuel cannisters still to be collected is shown on the left-hand side of the screen.

This fun educational game by Steve Bissell can help improve a child's mental arithmetic

Although LADDER ADDER is based on the arcade ladders and levels theme, the emphasis is on education. Four brick levels are drawn on the screen, each connected by a ladder.

You start at the bottom left corner of the screen and a golden crown is placed at a random position on one of the levels. Using the Z, X, * and ? keys you must climb ladders, run along levels and collect the crown.

Once you have it you'll be asked a simple arithmetic question and have to answer it before the fuse of a bomb burns down and it explodes. Answer correctly and the crown will be placed on a pole on the right-hand side of the screen and the bomb will be defused. Answer incorrectly and the bomb will explode and bang goes one of your four lives.

When you have collected five crowns you go via the door at the top right-hand corner of the screen to the next screen which features more difficult questions.

There are three levels of difficulty - selectable from the title and instructions screen - and five screens, each with five crowns to collect.

Defuse the timebombs before they explode, in Anthony Houghton's exciting arcade game

In this fast-action arcade game, you are given the task of guiding Bomb Squad officer Ben Bingley around the screen to find time bombs that have been placed by a malicious bug-eyed alien.

The screen is composed of tiles which Ben can walk over, but unfortunately, they crack and dissolve as he steps off them. This means he can't retrace his steps and he may sometimes become stranded on a tile surrounded by empty space.

There is a solution - the row of tiles he is standing on can be scrolled left or right providing nothing is blocking their path, so it is possible to move a tile towards him and have him step on to it.

Apart from becoming stranded, Ben must avoid deadly skulls and the bug-eyed alien that hops from tile to tile. Flags placed randomly around the screen can be collected for bonus points.