Vortex is a Mode 4 three dimensional space game, in which your spacecraft is pulled with increasing speed into a vortex, dodging marauding aliens as you go.
You have the obligatory laser, but the enemy's return fire depletes your protective shields quickly - and they don't often miss!
If you can survive this section, you then weave your way through an asteroid storm with no help from your laser. Should you get through unscathed you face yet more and faster invaders and asteroids.
Death results from a collision or being shot with no shields left, but you do have five ships. Your score depends on how long you survive and how many aliens you shoot.
The 3D effect takes time to get used to, as does the way your ship arcs up the screen as you move left and right. The fire button is auto-repeat so saving keyboard wear - a thoughtful feature.
The game is original, with clear, fast graphics - especially the moving background - com plemented by exciting sounds. It is well presented and profes sionally written and is as good as, if not better than, previous Software Invasion releases.
The on-screen instructions are very clear and concise. The game supports joysticks in addition to keyboard control and there is a sound on/off option.
My only criticism is that all the stages are similar in screen format - they just get faster - and this tends to monotony. Overall though, nice one. Software Invasion.