I wrote this game!
I didn't think copies of it made it far from my small circle of friends in Edinburgh. If anyone has a copy of this please contact me as I lost it when my house was burgled and all my ST stuff was stolen.
I must have had a demo of some sorts, because there was only the submarine level and I never realized until recently that other vehicles were available!
A straight forward shoot 'em up. Don't be expecting a space combat simulation, you just don't have enough freedom of flight. The only thing you have to do is shoot the enemy and avoid being hit.