Yes, you're correct in thinking that. The "trial version" is the full version of the game that hasn't been purchased, therefore there's no way to play the full version until 800 points have been exhausted on "unlocking" the game's DRM to your machine.
Yes, it is stunning. I never thought vector graphics could look that nice.
If it costs you $20, that's fucked up. It costs us 800 points here, which at a conversion rate of $1 to 80 points, 800 points = $10. The conversion rates for English Pounds or Euros may differ, I'm not too sure. I'd be interested to see the international conversion table, actually.