""The future of the series is now in question, as the feedback, user reviews and poor media attention has caught us by surprise," said Frozenbyte vice president Joel Kinnunen in a Steam update.

http://www.eurogamer.net/articles/2015-08-24-trine-3-dev-says-the-future-of-the-series-is-now-in-question

Yeah, well, I was caught by surprise by how much weaker this entry is compared to first two games - I'm guessing there are a lot of folks out there that feel the same.

This.

Trine 1 & 2  local co op is some of the most fun I've had with the Wii U... Not many good 3 player games out there when you think of it....

Trine 3 didn't look too bad. However I would have liked to seen more puzzles interwoven into the gameplay.

That 68 on metacritic hurts

On steam forum, you can read the reason for the problems with the game. They ran out of money so had to cut back on many things.

Too bad since Trine 2 was a good game. Now the series is likely dead :(.

Most people complain about the length and cliffhanger ending, but honestly, that's not the main problem with the game. Lack of skill progression of previous games and simpler puzzles are much worse offenders.

Still enjoyable, especially if played in 3 perosn co-op, but I'd advise for people to wait for the price to come down.

As for their budget - yeah, well maybe they should've made regular 2.5D sequel if they coudn't handle transition to 3D with that money - game is not better than the first 2, and they pissed off a lot of fans in the proccess.