The best reward first is the reactive armor, right beside the special locked reward, it gives you a extra life, kills most things near you when its gone, and makes you immune to things like biters before it is destroyed.
Once you get enough awards to pick a second reward, a great combo with the reactive armor is the hazard suit, which makes you immune to things like the acid splat, but try not to use it all up as it does not replenish. The hazard suit is the second to last reward on the top row.
Both of these together make you almost invincible for a big chunk of the game.
w/o cheat i got 4k, with it i got 404k... the cheat is zooming out on the internet explorer and throwing it (the zoom button is on the bottom right hand side, not sure for firefox)
I noticed a glitch on creating a level... if you have colorblind on and you put down a color, then change it to another color, it has the first color's shape
 "Amorphous+"){kind=icon}
 "Snotput"){kind=icon}
 "Hexiom Connect"){kind=icon}
 "Kongregate Chat"){kind=icon}
 "Areas"){kind=icon}