I always felt RCT1 had the best scenarios, some could call it "nostalgia" but I read an article about the remake of ClassicRCT (for mobile) that the original creator of RCT (Chris Sawyer) preferred the scenarios in RCT1 too. I think sandbox kills scenario mode, and I wish we had a "real" in-depth career mode.
With RCT1 and RCT2 you had a time limit and high score to each scenario, this gave them replayability. In RCT3 and PC the game feels more like you simply just have to wait for your profits to roll in, especially with the silly ride reputation system. Scenarios in RCT were usually under 10 years (with each year being a bit shorter) but in PC it can take a couple decades to make profits which is not as fun. Its not a matter of challenge, its a matter of patience.
Also in PC the objectives have become repetitive, there should not be so many challenges for gaining more guests, each challenge should be different and gaining more guests is the most basic of all functions, you build a ride you gain guests. There should be more coaster based objectives, thats the name of the game after all. But it seems like scenery is more important now.
Another unique aspect from RCT1/2 that is missing in RCT3 and PC, is that there is no variety to the shape or size of each scenario, and there is no land to purchase. Some people might say that isnt a big deal, and there are some scenarios where you cant change the terrain. For me, a big part of the classic RCT games was figuring out how to fill a tiny space with as much as you can. In PC its about filling in a large space with as many tiny little details (its almost the complete opposite) and I honestly think the classics felt much more like a puzzle game rather than a "paint by numbers" game
And RCT1 had a better progression to it. You started out with a simple junior coaster, than got a wooden, then got a looping, then a corkscrew, then as you progressed you unlocked more and bigger things. But in PC it just throws it all at you at once, and there is no balance. You can build 5 wild blues and make more profits that way, or you could build a tiny circle of a river rapids and make even more money, but a big coaster is just meh profit wise. Coasters should bring in the most guests
Just look at these examples of some great levels in classic RCT, what we need is a scenario creator/editor
[video=youtube;_ibuPTtYtoU]https://www.youtube.com/watch?v=_ibuPTtYtoU[/video]
[video=youtube;LbwtxpHe98c]https://www.youtube.com/watch?v=LbwtxpHe98c[/video]
remember beating a sceneario and having your guests clap and release their balloons?