The graphics are very cartoony. They are not realistic in any way whatsoever. The concept & graphics cannot compare to No Limits because that 'No Limits' is simulating the actual rollercoaster experience as real as possible.
In Sim Coaster, it is more of a fantasy land, with distinct themed area & rides. All rides are themed according to the area. You cannot create a faulty coaster. It'll go in a loop with a chain-life if it needs it! You can create a coaster where it can turn instantly 140 degrees sideways if you wanted. It would look odd and unrealistic, but it can be done.
The concentration is on the whole running of an amusement park business with your guests, staff, & attractions. You can build, but it won't be realistic... You can at least attempt to create the coaster of your dreams since you can bank at virtually any angle. It just takes time.
Never-the-less, it's still very fun.
It's just cartoony in a good sort of way!!