200,000 Points

At the bottem of the main menu press and hold L2 then O, then R2 in that order. Then let go of O then R2, then L2 inthat order. Then enter the numbers 750330. That should give you 200,000 points.

Easy Points

If you're begging to get some points to buy that monster you desperately want, play as Megalon and either do the "ACTION" or "SURVIVAL" games. In both games immediately start pounding your enemy with your beams fully charged. That should at least take half if not more of your enemies health. Once that is done, you'll have easy points to buy that monster.

Multiplayer Cheats

From the Main Menu, scroll all the way to the bottom, then press and hold L2, then press and hold CIRCLE (till holding L2), then press and hold R2 (still holding L2 and CIRCLE), then let go of CIRCLE, R2, L2. Enter the following codes: 259565: Player 1 does 4x damage 819342: Player 1 has Infinite Energy 531470: Player 1 is Invisible 338592: Player 1 is Invulnerable 927281: Player 2 does 4x damage 324511: Player 2 has Infinite Energy 118699: Player 2 is Invisible 259333: Player 2 is Invulnerable 500494: Player 3 does 4x damage 651417: Player 3 has Infinite Energy 507215: Player 3 is Invisible 953598: Player 3 is Invulnerable 988551: Player 4 deals 4x damage 456719: Player 4 has Infinite Energy 198690: Player 4 is Invisible 485542: Player 4 is Invulnerable

Regeneration

From the Main Menu, scroll all the way to the bottom, then press and hold L2, then press and hold CIRCLE (till holding L2), then press and hold R2 (still holding L2 and CIRCLE), then let go of CIRCLE, R2, L2. Enter Code 536117.

Health Doesn't Regenerate

From the Main Menu, scroll all the way to the bottom, then press and hold L2, then press and hold CIRCLE (till holding L2), then press and hold R2 (still holding L2 and CIRCLE), then let go of CIRCLE, R2, L2. Enter Code 122574.

Indestructible Buildings

From the Main Menu, scroll all the way to the bottom, then press and hold L2, then press and hold CIRCLE (till holding L2), then press and hold R2 (still holding L2 and CIRCLE), then let go of CIRCLE, R2, L2. Enter Code 812304.

All Cities

From the Main Menu, scroll all the way to the bottom, then press and hold L2, then press and hold CIRCLE (till holding L2), then press and hold R2 (still holding L2 and CIRCLE), then let go of CIRCLE, R2, L2. Enter Code 659996.

All Monsters

From the Main Menu, scroll all the way to the bottom, then press and hold L2, then press and hold CIRCLE (till holding L2), then press and hold R2 (still holding L2 and CIRCLE), then let go of CIRCLE, R2, L2. Enter Code 525955.