Dead Space Ignition is hardly a game, but the mechanics that drive the hack types are varied. There are three hack types: Trace Route, System Override, and Hardware Crack. Each of them is a puzzle of sorts, but none of them are much fun to play, unfortunately.
Trace Route is my personal favorite of the three, though that's not saying much. The object is to guide a consistently moving bit of code to the end of a linear maze. You'll need to move laterally to avoid data libraries, which slow you down. There's a host of other obstacles that will get in your way, but there's a way to deal with all of them. For example, if countermeasures get ahead of you, you can draft behind them to gain speed. You can also drop firewalls to slow them down or deploy other attacks to confuse them. Be careful, though; lots of those attacks can be used against you.
System Override plays out like a tower-defense game with a major twist; you are the attacking force. Your job is to deploy a number of virus types in order to overwhelm the system's defenses and get through whatever it is that's impeding Franco's progress. Standard virus types fire at enemy emplacements, while others can disable or confuse them.
Hardware Crack is a variant on the classic mirrors-and-light puzzles that are often used in Zelda games. You'll have to get certain colored beams to their proper receptors through careful placement of mirrors and junction boxes. Sometimes you'll have to use a special device that splits beams; other times, you'll have to use those same devices to combine two colors into a whole new one. It's dull and occasionally confusing.
If you don't see yourself playing through Isaac Clarke's next adventure next January, ignore Dead Space Ignition. If you know you're going to be purchasing Dead Space 2 and want to see what this is all about, proceed with caution. There are two ways to try this game out. It's being offered as a free reservation incentive to those who put a deposit down on the game. The less appealing way to get it is, of course, to plunk down some Microsoft Points. It's cheap, to be sure, but free or not, you won't get much more than your money's worth. Still, it won't even come close to putting you off the series as a whole. Dead Space 2 can't come soon enough.