To unlock more rewards on a higher difficulty level, go to GENERAL OPTIONS and pick the desired difficulty. Then, go to "Advanced Options" and turn down the CPU skills while turning up the human skills.
To get a goal easier, do a wrap round. Go to the other side of the goalie and shoot.
Note: This does not always work.
Press R(2), L, Left(2), Down, Y, R, Y, L, Up, Right, Y, Down, Left(2), Y, R, Down, Up at the game modes screen. Exit that screen then enter the cheat menu from the main menu. All tasks should now be marked as completed. All cheats can now unlocked individually by selecting them. After doing so, you can go to the team selection screen to choose any previously locked team, select the previously locked jerseys, and play the air hockey, mini rink, pond hockey, and speed hockey mini-games.
At the game modes screen press R, R, L, Left, Left, Down, Y, R, Y, L, Up, Right, Y, Down, Left, Left, Y, R, Down, Up Unlock everything (access cheat menu)