Is Planet Coaster 2 a good sequel. Well my review would help that. First let's take a look at the pros and cons.
Pros: New path system (Which is great), water slides added, new coasters (Vekoma tilt coaster, Intamin multi-dimensional coasters, Mack rides super splashes, and E&F Miler water coaster), scaling tool introduced (You can now create better artwork), paths included in selection tool, staff paths introduced, water and electricity utilities introduced, counters introduced, amazing coaster smoothing, you can now theme your coaster trains, you can now theme your flat rides even more, you can now theme your track ride trains, introduction to moving platforms for scenery, you can now create plazas (With the aforementioned new paths), demolish brush introduced (For easier demolition), weather is introduced, manufacturers introduced (With play-on words), names of colours (On colour picker) introduced,
Cons: Can be buggy, no functional hotels, no security, some rides missing from first game (Arrow suspended coaster for example), you can't change the train types, not a lot of pre-built animatronics, RMC topper track still has Gravity Group trains, Arrow 4th dimension coaster is still "For all ages", not a lot of food/drink/gift options, career mode is mostly buggy, no steam workshop :(, no interactive rides, water rides (Not the water slides) don't need water supply (Which is not specific enough),
Note: There might be more pros and cons. But, I think I should recommend it. Another note is that I got it with the vintage funfair rides (And it's not the pre-order)
I'd recommend it if you want a better game with new features. But it's still work in progress. And yes, it's still new.
Anyways, I want some things improved (Including the fixing of all the cons I listed) along with new features like a custom ride type creator (Coaster, flat ride, and tracked ride), new flume elements (Like the ProSlide elements), lighting on slides (To create various patterns), pre-shows, screen based rides (Motion simulators, flying theaters, cinemas, etc.), walk-throughs, parades, concerts, combine path extras when making paths (Like have benches and bins at the same time when making paths), the works.
I'll post my update ideas on Reddit in the future and will send requests to Frontier.
I recommend the game because of the pros.
But still, it needs some work done.

I like the game, but unfortunately, I have to leave a negative review. Why? Because it's really frustrating when companies withhold content from the base game and sell it as "DLC" or "bonus" content. It's a scummy practice, and one that Frontier seems to do regularly. I know it's not the developers' fault—these decisions come from the higher-ups. It's a good game, but leaving a negative review is the only way to voice my displeasure with this kind of practice.

I really enjoy this game. Not so much the career mode, which I think is inferior to the career mode in the first game. Career in PC2 seems more challenging, sometimes frustratingly so, and also the parks seem a little less inspired.

I particularly enjoy building items. I have enjoyed creating things in this game to an extent I did not in PC1. The creative element has so much potential and I enjoy creating things in sandbox mode.

So why do I not recommend it?

There are so many flaws, so many little qol problems. This game has the potential to be amazing. But unfortunately, it appears that it was released in an unfinished/underdeveloped state.

Why is it that when constructing something you sometimes lose advanced control of items and other times you don't?

Why is it that sometimes you can group items you are constructing together and other times you cannot?

This game lacks so much finesse for fine controls and usage. For example if you are trying to manipulate something large the controls will sometimes be in the middle of the item or at one end. So if you are trying to finely manouvre it to fit in with existing items you will spend far more time than is really necessary to manipulate that piece into place as the controls must remain on screen to control the item but that means you have to zoom out to such an extent that you cannot see clearly if the item is correctly in place. Its very fiddly.

Then we have the crashing. I haven't had a lot of issues with crashing generally. I created a large building to use in my parks only to find after completing it that there is a limit to 4000 pieces to save something as a blue print. I can't even manouvre the item within the map it is created in. Why was this a surprise to me? Why did the game not make this clear before I spent a million hours creating something?
So now, in order to use the item that I spend hours creating, I have to build a park around it. So I really started to get into creating this park around my creation only for the game to crash repeatedly. Over and over. Place a path - crash. Place a ride - crash. Its so frustrating.

Basically, this game was rushed out unfinished and with underdeveloped tools and UI. There is so much potential in this game with a significant amount of further development. I doubt the inevitable succession of 'updates' and hotfixes will amount to the amount of work needed to make things as functional as they should be. But I hope the dev proves me wrong.