A blast from the past, and a very fun experience.
I wouldn't call it simulation because you can do in one minute what the real Tony Hawk does in 10 broken knees, but it's really fun, featuring a series of open levels with 10 objectives each that vary from simple "get this many points" to "find the secret tape".
To me this is a great example on how to make a game fun just with gameplay. No story, no enemies, no bosses, just you doing combos. It's kind of like playing a yoyo, I could explain to you how it's made or how resistant the string is but only when you try it you would realize how fun it is to learn tricks and the satisfaction in doing them.
The only flaw in my opinion is the fact that you can't continue your chain of combos after jumping from a half-pipe, so if you want to have a big combo chain you will be forced to grind a lot.
And maybe the game is a bit short for today's standards.
Other than that, an impressive game.