No Limits is a coaster building "game", which allows the user to build and ride coasters. A demo can be downloaded at www.nolimitscoaster.de. The full version includes a complete editor, several sample tracks, and several types of coasters. The full version costs $25 USD.
New: There is an update to NL that includes an importer for RCT tracks, so players can ride their RCT creations in No Limits. Due to differences in the physics of RCT/No Limits, the importing may not be perfect.
I have a few screenshots and a few basic tracks for download
An aerial view of a coaster
Another aerial view
Viper at SFMM
Another view of Viper
A "crashed" coaster, resulting from block brakes being too short
Flashback at SFMM. Finally we can ride this thing without any of the head banging. I heard that there is also a Windjammer recreation.
Another shot of the "Clippy Coaster"
Intel Inside coaster car, going up into a tunnel
Intel Inside car again
The station platform
The mid course brake run
"It looks like you're riding a coaster. Would you like help?"
Here are a few basic tracks that I made in the editor. They are nothing fancy, but show what can be done.
Boomerang Coaster - A simple launched ride
Out and Back coaster - One of my first NL track designs.
Dive Machine - A NL ride with a vertical drop, many trains, and several inversions
Launched Multi-looper - Multilooping coaster that starts out with an Incredible Hulk style launch tunnel, which fires when the train is halfway up.
Hyper 2 - An out and back hyper coaster
Launched Mega Coaster - One of my first recreations that would probably be impossible to engineer in real life.
Portable - My first attempt at creating a portable coaster
Bushfire - A B&M style sit-down with several unique inversions including an incline loop and a pretzel.