This game is a novel variation of the old Invaders theme. You are greeted by instructions. Killer moths are threatening Earth. There are ten "boxes" at the top of the screen. Between the fifth and sixth is a large moth. Small moths fly into their boxes in sequence. When a box is full, one moth is released, and it will fly down and try to destroy your laser. This is controlled using Z, X and COPY to fire. Joysticks may also be used. The large moth at the centre of the screen cannot normally be killed, but each time you manage to kill 200 small moths, it will be released. It must be destroyed before it lands or else you lose a life. Once it has been destroyed, a set of more powerful moths will attack as before.
Bonus laser-bases are awarded if you score 10,000 and 20,000 points.
There are six skill-levels. Pressing ESCAPE at the end of a game gives you the chance to change the skill-level but also resets the high-scores. You may start at any of the six skill-levels.
Graphically the game is good. The moths are realistic, the central one particularly so. All movement is very smooth; a lot has been done in the preparation of the game to ensure this. I have examined the code, and the game is very well written.
The sounds are also good. It is quite amusing just to listen to the game, as the moths will fill their boxes, each makes a different sound. The other sounds are fairly complex and the envelope facility of the Beeb has been used well.
The game is fairly fast and needs quick diving from side to side to avoid the falling bombs from the large moth, so you need to have a fast reaction time. Yes, your children will beat you! The various elements fall together very well to provide an enjoyable game.
Summary: Good game, interesting variation on well-used theme.