I am up to level 35, everytime I manage to win and they say congrats etc and the fishes swim across etc I do not move on to the next game I seem to be stuck on 35, it has happened four times now. I don't want to spend any money but why don't a pass on to 36 pls ? puzzled gran !
Eccles Cake is right about that being the last one in a phase. You should get a short cartoony thing saying something like 'well done' and moving you on, as it did after level 5 and level 20. Try looking up and left a bit from level 35 to see if a barrier is there or even if level 36 is available. Good luck.
If you wait a few days you will automatically go through to the next section. Otherwise you can change the time setting on your phone to a few days in front and that might do the trick.