$1,000,000 (in 2D game)
Select City Info, Budget from the menu. At the Budget screen, hold [R1] and press [X], [Circle], [Triangle], [Square]. Release [R1] and hold [L1]. Press [X], [Circle], [Triangle], [Square]. Release [L1] and hold [R2]. Press [X], [Circle], [Triangle], [Square]. Release [R2] and press [L2]. Press [X], [Square], [Triangle], [Circle]. Release [L2]. The sound of a cheer will confirm correct code entry. Note: This code may only be enabled once per game.

0% interest bonds (in 2D game)
Select City Info, Budget from the menu. At the Budget screen, hold [Triangle] and press [L1], [L2], [L1], [L2], [R2], [R1], [R2], [R1]. Note: This may result in fines of up to $100,000.

Most tools available free (in 2D game)
Select and cancel the tree tool with the normal arrow cursor. Go to the status bar. Press [Up], [Down], [Right], [Left], [Up], [X] while keeping the cursor within the status bar area.

Maximum fire, police, and military (in 2D game)
Select and cancel the dispatch tool with the normal arrow cursor. Go to the status bar. Press [Left], [Right], [Left], [Right], [Circle], [X] while keeping the cursor within the status bar area. Use of any of the dispatch tools (fire, police, military) to get the maximum number allowable, regardless of the number of stations you have.

Helicopter cockpit (in 3D game)
Press [R2], [L2], [R2], [L2], [R2], [L2]. Turn off the cockpit by pressing [R1], [L1], [R1], [L1], [R1], [L1].

Night (in 3D game)
Press [Down], [Up], [Down], [Up], [Down], [L2], [R2] to cycle day and night. To return to normal, press [Down]x2, [Up]x2, [Down]x2, [L2], [R2].

Fade to black (in 3D game)
Press [Down]x6, [L2], [R2]. To pause the fade, press [Left]x6, [L2], [R2]. To return to normal, press [Right]x6, [L2], [R2].

Translucent city map (in 3D game)
Press [R1], [R2], [R1], [R2], [R1], [R2], [R1], [R2]. A translucent city map HUD with a position indicator will appear. To return to normal, press [L1], [L2], [L1], [L2], [L1], [L2], [L1], [L2].

Gold nugget trail (in 3D game)
Activate the helicopter cockpit code multiple times by pressing [[R2], [L2], [R2], [L2], [R2], [L2], [R1], [L1], [R1], [L1], [R1], [L1]] seven times, followed by [R2], [L2], [R2], [L2], [R2], [L2]x2, [R1], [L2], [R1], [L2], [R1], [L2], [R1]. A trail of golden nuggets will appear on the road. Collect these nuggets as you move around the city to increase your city fund.

Slot machine mode
Start a new game and select the "Recreation" icon. Then, move over the "Marina" icon and select that feature. Build the marina near a water section. Select the "Budget" icon and enable the "Legalized Gambling" option under the "City Ordinances" menu. Use the "Query" tool to highlight the sailboat, then press [L1]. A slot machine will appear. Press [Circle] to stop the slots at a cost of $100 per attempt to win various buildings or disasters.

See person in the car or plane
While driving the plane or car, [R2] + [L2] and press [Left], [Right], [Left], [Right], [Up], [Right], [Square], [Triangle], [Down]. The screen will fade to black then return. You will now see the entire person from the back.

Flight mode (in 3D game)
Press [Right], [Left], [Right], [Left], [Right], [L2], [R2], [Start]x2. The code [Right], [Left], [Right], [Left], [Right], [L2], [R2], [X]x2 may also be used. Press [Start] to return to normal. You can fly around the city without being limited to the roads. Flight mode controls are:

[R1]: Altitude up
[R2]: Altitude down
[L1]: Propel forward
[L2]: Propel backward
[Up]: Look up
[Down]: Look down
[Left]: Turn left
[Right]: Turn right

Alternate music
Pause game play, then press [L1], [L2], [R2], [R1]. The music will change when the game is resumed.

In-game reset
Hold [L2] + [L1] + [R2] + [R1] + [Start] + [Select] and the game will start over.