Investing in the Iron/Silver/Gold/et cetera Heatsinks upgrades makes Reactor Plating a much better option than Heat Vents - not only are they more cost-effective, but they also can't overheat. Heat Vents probably need some sort of major buff to make them a more worthwhile option to compensate for requiring actual planning.
An undo button would be a great addition. I've made a stupid mistake just before completing the level more than once. And in some levels, redoing the first part that you have completely figured out just to take another shot at the second part gets a bit tedious. For now, 3/5.
The mechanics are clear and simple and the levels are fun, though Toshi's voice alternates between hilarious and annoying (yes, I enjoyed responding to the latter with a baseball to the head). Got 130 stars rather easily. Yes, you have to earn more than 3 on some levels. The key to that are the wooden blocks - you can destroy some in one shot rather than two if the ball rebounds, and you can sometimes hit more than one block with one shot. All in all, it's a cleverly designed and fun game. 5/5
How about a mode where the guards are killable, but your target tends to stick to them? That way, you'd have to pick the guards off one by one when they're alone.
A minor nitpick:
It'd be nice if the game didn't return you to the main menu automatically after you die, instead giving you an instant "retry" option. It'd be even better if you didn't have to switch back and forth between the mouse and the keyboard for that.
Gadzooks, Gordzak
Dude! You just completed the Gadzooks, Gordzak achievement in Hero's Arms and won the Gadzooks, Gordzak badge and 30 points!
"Gotta Kill 'Em All!"
Dude! You just completed the "Gotta Kill 'Em All!" achievement in Hero's Arms and won the "Gotta Kill 'Em All!" badge and 30 points!
Gordzak was disappointingly easy.
The last one is quite easy with the following strategy: From the left boiler connect to an alternator set to 50, and from that to a jackhammer. From the right boiler connect to a control valve, and from that to both ducking and going forward. The strategy is to keep walking forward and ducking his shots until you get in a place where you can hit him even when he retreats to fire.
Necronomiconquerer
Dude! You just completed the Necronomiconquerer achievement in The Necronomicon and won the Necronomiconquerer badge and 60 points!
Finally...