I will not talk mention the lack of customization and dedicated servers here because it was communicated that the game will not have those. For Lagoon i make an extra section.
Positive:
New blocks for Valley are awesome!
The art direction of the game is quite nice. New textures, music, car models and look of the UI, very good.
The campaign maps are fun and look good with all the objects and stuff in it. Some Canyon maps feel overboosted i guess the "Turbo" theme is real.
Valley dirt maps

Online Room system seems to be implemented well. Even tho changing the name of the room would be nice.
Negative:
Ranking: No possibility to view ranking list of individual maps and the replays.
Map sharing system:
- very basic, limited sorting
- it seems to be not possible to copy Maps into a folder so that they appear in game
No dedi records feature online, even tho Like/Dislike system is in place and also a counter how often a map gets played.
Lagoon:
Firstly, it seems it has a huge amount of blocks and it looks quite good.
But the handling, we get the same crappy loop (wallride) handling again (3-1-5 and 3-1-6).
Canyon has it, Valley has it, nobody likes it, blocks are barley used in custom tracks and we get it AGAIN.
Why 3 times the same thing, why not a bit diversity here, why not learn from the popularity of Stadium Fullspeed servers, i really do not get this.
Rollercoaster blocks are pretty unsmooth would have expect different but i can maybe even enjoy it after a while.
Beach blocks excellent idea, gameplay of these blocks reminds me of Valley dirt and as we know many people did not like it very much.
Wood blocks ok i guess. But the normal platform set is missing completely.
Overall i personally expected a different gameplay for Lagoon, much more different from Canyon and Valley. To be honest in a way it feels more of the same we already got. With the same "mistakes" that already annoyed players in Valley and Canyon.
Conclusion:
Overall a good game. The negative points could have been easily avoided with more time and also maybe will be rectified with patches.
Lagoon gameplay idk maybe i still need more time to learn it. But as we know players nowadays are not very patient.