I assume this game adds to the Hyper Rails simulation from 2002. The game engine itself was fine, but there were things that could definitely be improved.
For instance terraforming wasn't an option, so it'd be nice to see this. When it came to adding brakes to the coasters you had to do it via nodes, so if you wanted a long brake run you had to put down 8 different nodes and you had to adjust each individual node's power because one node has the ability to stop the entire train. As far as the coasters themselves I believe the following designs were available:
Looping (Viper)
Stand Up (B&M)
Inverted (B&M/Intamin)
Hyper (Goliath style track/trains)
4D (X2)
I guess more design choices are in order like wooden coasters or maybe newer ones like Intamin and Rocky Mountain woodies! I recall the lift hills being prefabricated and any modifications to them weren't possible. I guess that was because of the elaborate stairs for the them. There were different station styles you could choose from which mattered when the coaster was finished because of the ability to walk around in the park and progress through the station's Que system.
I guess all in all I'd like there to be atmosphere to the park when it's all done. This would be great because that's the one thing I didn't like about No Limits. Coasters in empty lots are not fun. That and in RCT the guests screaming and laughing really added to the experience.
Edit: Upon review of the trailer it seems terraforming is possible unless the park was built like that and no custom terraforming is available. Also, I just remembered some elements like the curved drops being prefabricated too, so I hope modifying them is possible like it should with all the elements.