Hi Ronayne,
As martinvk points out, they're not exactly cheats. They're little things a programmer writes into the code when the boss isn't looking. Well so they say! They're actually called Easter Eggs, and they appear in most games. It's up to you to find them.
Some people say these don't work with TRS 2006, but I'm sure I've had success with some. Just try them and see how you go. By the way, I got most of these from a previous post by Hiballer. Thanks mate.
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The Alt commands apply to TRS2004, but as I said, some or all work with TRS2006.
Alt-FLY takes you up in the sky and you can steer yourself in any direction.
Alt-WALK puts you at ground level and lets you walk on the ground in any direction.
(Also try ALT+WALK / ALT+Y ALT+U )
Alt-SMITE lets you click on an object and lightning strikes it and produces a hole in the ground to a thunderous crash out your speakers. Beware!. Be VERY CAREFUL using this.
Alt-MMMG (Make My Map George) makes you a new route on a new set of train boards, any size, but the effect diminishes with distance from where you start the command.
Alt-LUCYINTHESKYWITHDIAMONDS turns the sky into a kaleidoscope A-La The Beatles.
Ctrl+Alt+Shift+CARZ, then click on a moving car. (take a drive and watch those trainz!)
Hit the Esc key to stop all this nonsense.
Good luck.