Zalaga is a very successful variant on the "blast 'em out of the sky" theme. The aliens
swoop in from various directions to form themselves into a Galaxians type layout at the top
of the screen. Once this is complete, they swoop down on you, while at the same time
you are trying to shoot as many as possible of them. A screen is completed when all the
aliens are destroyed.
Interspersed between these standard screens (which grow steadily faster and more vicious)
are the Challenge Stages, where the aliens fly around in set patterns, the object being to
shoot as many as possible while they remain on screen. It is also occasionally possible to
summon up a second fire base to act in concert with the current one, doubling the fire-power
(and target area).
One very good point about this game is that it does not become tedious once you get good
at it, as games addicts who've tried it will testify. The sound and graphics are very
good, the latter being both fast and smooth, even if occasionally the aliens do disappear
for a short time owing to a slight timing fault. This problem is not severe, and is hardly
noticeable once you get engrossed in the game. The handling is very good, the controls
are simple, and a nice touch is the scrolling backdrop of stars.
Overall, this is a superb game, probably the best game of its genre with the inevitable
exclusion of Acornsoft's Planetoid.