Whole divisions of enemy panzers are about to breach the anti-tank barriers to be let loose on your HQ. With only three tanks left, can you stop the invasion and prevent an unconditional surrender?

Moving east and west you can elevate and lower your tank's gun turret to alter the trajectory and range of fire.

The battlefield erupts in explosions as the enemy fire back - unfortunately their fire is horribly accurate - but it is possible to knock out quite a few before you go up in flames.

The enemy tanks move from right to left across the screen descending towards the anti-tank barriers. Once they've reached this point they are below your gun barrel depression and it's impossible to hit them.

It states in the cassette inlay that once ten tanks have penetrated your defences the game ends; in reality, only five have to get through to your HQ to end the game.

Some tanks appear as 'ghost' tanks - mere shadows compared to the test. I'm not sure whether this is meant to portray distance but ten points are still awarded if you manage to blow them up. Far more difficult to hit are the red tanks which seem to appear at random and move at a faster speed.

There are five difficulty levels, although I wasn't able to determine much difference between them. In fact, I scored higher on level 5 than on level 1.

Tank Battle is enjoyable to play with the added incentive of trying to beat my previous best in the Hi-Score charts. However, control is with the TI joystick which is exceptionally uncomfortable to use and very unresponsive - the game would have been much improved with a better joystick.

Using an Extended Basic cartridge, Tank Battle is available from Temptation Software for the TI99/4a at £5.95.