Master code:
During gameplay, press Select, , Up, Up, , Down, Down, , Left, Left, , Right, Right, , Up, , Left, , Down, , Right, , Up, Up, , L1.

Full special:
During gameplay, press Select, , Up, , Down, , Left, , Right, , Down, , Up.

Invisible board:
During gameplay, press Select, , Up, , Down, , Left, , Right, , Left, , Up.

Shark surfing:
During gameplay, press Select, , Up, , Down, , Left, , Right, Right, , Down.

Paddle faster:
During gameplay, press Select, , Up, , Down, , Left, , Right, , Down, Down.

Thanks to Revolution reader Marcus K!