Extra bullets:
Press Select during the 3D building levels to exchange life points for ammunition.

Level select:
Wait until one eye flashes during demonstration mode. Then, press Start and hold Up + A + B on controller one and Up/Left + A + B on controller two. Then, press Start on controller one. Enter one of the following codes to start at the corresponding level.

Level	Code
1	00
2	08
3	0A
4	12
5	1E
7	32
8	38
9	3B
10	40
13	49