TEN LINE ORIC BASIC INVADERS

Ten line BASIC challenges are thing I've had a few goes at, but a classic invaders game seemed a bit too much of a stretch. 

Then a recent competition showed a really nice version for the Acorn Electron. Looking at the source, it took advantage of abbreviations e.g. G. instead of GOTO - unfortunately the Oric does not allow this. 

But I thought I would have a go anyway, and managed to squeeze in the following:

• Scoring (wow!)
• Increasing difficulty level (each new wave starts lower down)
• Sound effects (double wow!)
• Even some cosmetic effects like an asterisk when an invader is hit.

You might tell that I'm kinda pleased with this one, wasn't sure I could do it.