Invaders is the poorest program that I have seen from Superior Software, a company usually linked with good software for the Beeb. The idea is to kill the rows of aliens before they land. You have three bases, and bonus bases are earned at 1,000 and 2,000 points. The controls are Z and X for movement and COPY for fire. I presume that the choice of fire key is to reduce wear on the RETURN key.
Each time you clear a board of invaders, a new set appears. These are faster, start lower down and fire more bombs. There are two types of 'mothership', one worth a mystery value and one worth 600 points. Both drop fast bombs which simply blast straight through the bases.
There is a top ten high-score table in various colours. This is the best feature.
Unfortunately the game is nowhere near as good as some Invaders games. There are only three types of invader and, even though these characters are multi-coloured, good use has not been made of the graphics facilities. Mode 5 has been used and the characters are all rather chunky. Their movement across the screen is rather poor.
The sound quality is also low. There is a very persistent, single tone Beep for invader movement, and this is very annoying. The other sounds offered leave little to be desired.
The "instructions" given are the bare minimum possible, and this is poor; this should have been remedied.
Altogether the game is not up to Invaders standards. At £7.95, it is overpriced.
Summary: Overpriced and poor. More thought is needed. Other Invaders games leave this one standing.