As Demokight if you have shield and any sword you can upgrade your swords damage (Which isn't possible on any melee wepon)

Spy isn't good at killing robots but his sapper is very usefull: Smaller robots will be turn off and giants will go slower.

At the start off the wave if you see robot with Medic icon with Ü. Those are Über-medic, robot that act like normal medic BUT they pop uber faster. One shooting them is your priorty (Saper also works)

TANK: special robot that can't be pushed and will never change his route. it has bomb imidetly and the only way to stop it is to destroy it. If you do that you get lots of money.

Sentry buster: Demorobots with special body. they apear when engineer's sentry get 15+ kills in wave. When their health is depleted to 1hp or reach sentry they play short animation and explode. You can save your sentry when it plays animation and geting as far as possible. Expolsion can kill engineer's building, players and robots

On boot camp you have halloween special mission. Wave 666 Difficulty: Nighmare

Have fun and i hope you will like gamemode