There's nothing new we could tell you about Space Invaders, so, unfortunately for Supernova, that only leaves the conclusion.
The invaders in this version move excruciatingly slowly, even when there's only one left on screen, the collision detection is dodgy (shoot through your barrier and you take out either a whole bullet's width, or absolutely nothing no matter how many times you fire) and the sound is best left turned off.
Bringing a classic like this to the Amiga is not such a dumb idea: after all it has, and always will have,a place in the hearts of most computer owners. But to produce a version like this, and expect people to buy it is shameful. If you really want to play Space Invaders, there are many better PD versions which will entertain you rather than make you kick yourself and reach straight for the rubbish bin.
Instead of buying this, you could grab yourself a copy of the PD game Amoeba Invaders, given away free on the cover of ST/Amiga Format Issue 5, or from Fish Disk Number 120.