I just got Contra 4 and it's awesome indeed! Easy mode is almost as hard as Super C for the NES.
The instruction book reads like something a PG version of Maddox would write. Check out this comment from page 18:
Multiplayer Mode
Cooperating with a Friend - the True Contra Experience
If you know someone else with Contra 4, you can celebrate the time-honored tradition of taking all the good items and advancing the screen too quickly while playing alongside a friend