Qix is kinda old, but there really hasn't been a game like it since.

You have a marker that you have to use to block off portions of the playfield. The portion you get is the smallest area that doesn't contain the Qix (which is the pulsating line-thing in the middle of the screen.

You can either draw fast or slow. Slow gives you more points, of course, but is way more dangerous. So, what you want to do is carve up little sections using your fast draw

And then make the last section with your slow draw

Bam! Huge points!