Of course, you won't be able to just waltz right through each stage. There are multiple guards and creatures that will stand in your way, as well as obstacles that can be used for cover. Some enemies will shoot bullets, some will just punch, others will use fireballs. The enemies also differ in strength and quickness, with several requiring multiple shots to bring down.
Your character has a standard machine gun and cannon (which packs a more powerful blast) to use against the enemies. There are also a few Super Bombs at your disposal that will wipe out everything in your view. It's important to note that you have a limited supply of ammo, so you should know when to shoot and when to just run away. Fortunately, your character can hug the walls to avoid enemy gunfire and packs a mean punch if you run out of bullets. The only drawbacks to the game are the repetitive action (which is inherent in nearly all early arcade games) and some slowdown that occurs when a lot of enemies appear on the screen. There are also some annoying disappearing floors and conveyor belts that need to be crossed, which are rather difficult since they are so narrow. There's little room for error.
Overall, Crack Down is a fun, strangely addictive game that combines some strategy along with the action. Each level becomes more difficult than the last, with an increasing variety of enemies and dangers such as bottomless pits or acid pools. The fact that you must often avoid the enemy is a refreshing change of pace from the mindless shooting in similar action titles. One of the better things about this game is the two-player mode, which makes the game a bit easier to finish. Highly recommended, but think twice if you're not expert at this kind of games :)