Here's a few tips for the 200 000 points :
- Go to the harbor arena
- Use the military truck (upgraded)
- Try not to drive into fat zombies (green ones), instead try to drive as close as you can to them, and as fast as you can. This will make them explode and take some of their mates to hell with them..
- Pick up health as soon as it pops on your screen, because they don't stay here forever (I don't know if it's random, but no health for me during waves 12 to 17..)
- Focus on the path you take and try to keep the speed up, if you stop for too long you're dead.
I got it on my 3rd try (624 500 points), so I hope these tips will help you.
Happy achievement hunt !