Reward yourself with killing a lot of screen people – there are hundreds of them (especially in bonus levels)! You are given a huge number of murder options – ammo, weaponry, and angles of shooting and blasting the TNT inside the levels. Your goal is maximally bloodthirsty – kill everyone as effectively and efficiently as possible (to earn from 1 to 3 stars for excellence).
In regular levels, where, unlike bonus ones, every shot counts, it is necessary to shot your enemies dead with only this amount of bullets as you have – which at times seems so small! You will be facing hindrances like turns, rotating shutters, and others. Not killing everyone means failing the round.