SPEED DEMON Achievement
Get 100% score with the trap.
Towards the end of every level there will be a boss fight. When you've attacked the boss enough and their health is low you will be promted to press too throw out a trap. During this you will see a bunch of random buttons to press, if you press every one fast enough and without screwing up any of them, then the achivement is yours. It also get's a little bit easier if you play online and the other players shoots at the ghost at the same time you are trying to capture it.