This flip-screen shoot-'em-up and its very similar (but slightly souped-up) sequel are notable in a number of ways. For a start there's the colour - absolutely loads of it littered about, especially when programmer Raf Cecco's famous explodey bits come into play. Then there's the gameplay - the first few screens aren't too tricky, but you soon find yourself coming across some of the most ludicrously packed and complicated problems ever - it's often a real triumph to get half way across a screen, let alone onto the next one! Neat touches like the use of gravity (some bullets drop in a little arc as opposed to zooming on in a straight line, and your ship squats firmly on the ground if you don't tell it otherwise) add to the infuriating fun.
Raf's been quite generous in one way though - if you find you're having really insurmountable problems with any one obstacle you can always sacrifice a ship to get past it with the few seconds of invulnerability that come with each new one (I wouldn't recommend you try this tactic too often though!). A couple of essential purchases.