From TGDB.net

Cheats

Cheats:

 Press [CTRL] with [SHIFT] and type: cheater-cheaterwimp
 This cheat gives $1M plus all the supplies you can store.

 You can run the booming metropolis shown in the demo if you do the
 following: First run the game, then open SYSTEM menu and select the
 SAVE option. Save the game and then exit. Then run the game again and
 simply load your saved scenario. That should give you the demo city.

 If railway moguldom bores you and you'd rather see some groovy
 graphics on the ending screen, then, while the game is running, press
 and hold [CTRL] and [ALT] and type: bellybutton.

Infinite funds:
 800A6230 9400
 800A6232 7735

Infinite Money:
At the title screen, press L1+L2+R1+R2, then press Square+Triangle, and press
Start. You will enter the map selection screen. Hold L1+L2+R1+R2 and press
Circle. If you press correctly, you'll hear a sound. To increase money in the
game, press Start to pause the game, then press Left, Right, Up or Down to
incease the amount of money.

Submission:
Yohannes Aditya (yohannes@netexecutive.com)