is all about physics. Your job is to guide Joe across the level and get him safely to the end point without causing too much damage. You do this by tapping the screen (or pressing any face button) to activate the various magnetic pads that are close enough to Joe to affect him.
Each pad has a direction on it, and that is the direction it will pull your character. Basically, the game is all about knowing how you will be pulled in order to guide Joe to your goal. Of course, it's not as easy as it sounds. Along the way, you will be faced with various enemies that will either just bounce around the screen or actively shoot at you. There will be spikes on the walls that will hurt you when you hit them. There will be other items that are also magnetically charged that will cause your character to lose a heart and, then there are the boss battles that have very particular weak spots that have to be hit just so, else you will take damage.
However, you will get help along the way. These typically come in the form of various pickups that will do everything from flip the direction of gravity on the field, to increase the magnetic pull of the level's pads to shrink Joe to a smaller target, to turn off gravity, and even put you in a jet pack to give you direct control over Joe's movement.
Each level can be played in three different ways and each manner can be put on Normal or Hard. All that last setting determines is the number of hearts or hits you can take before you have to start over. The three different gameplay modes are Classic, Time and Collect.
Classic behaves just like I described above. Your only goal is to get to the end of the level before your hearts run out. In the Time Mode though, you have a ticking clock that you must beat and in Collect, there are various statues scattered throughout the level that will earn you different trophies depending on the number of them that you pick up before exiting the stage.
There is even an online component that allows you to go up against your friends and attempt to race through the levels you've unlocked.