Unlock 'free ride' gadget which starts you off with one of the contraption, if it isn't CFT just kill yourself and start again. Once you have the CFT it is all up to you to get to 800. I also had the slower missiles as they are easy to avoid. Remember you can teleport through the sparky things if one is coming right at you.
With thanks to X509Cert:
final point - if you fail, simply click the pause button, and retry - you'll be back in your CFT!!