Tony hawk 2 + the reverse trick and new maps.
Hard because, mainly, it's the exact same game as before, with new levels.
The only new thing would be the reverse, a move that lets you tie half-pipe jumps with a manual.
So basically this means that you can now do all kind of tricks inside a combo, and get millions of points this way.
And now the new levels: While I find the foundry truly horrible, I think the rest are a step forward in level design, full of interesting places to do combos.
In the previous game, I usually spent most of my time in the same areas, without exploring the level as I did my combo chains.
This whole situation makes me think about what it means to do a good sequel. Should I bash this title for just including one improvement and keep the rest as it was, or should I remember how many games can't even do that?
In the end though, is just about how fun a game is, and I completed career mode three times so I guess I can't complain.
So, in conclusion, the game is technically better than the second one, but it deserves less of a score because it builds little upon it.
But keep in mind I'm reviewing the psx version, without improved graphics.