Only a short session on this today, but I did play for long enough to complete all of the rest of World 3 (including a secret level). I died for the first time too – on the end of world boss. En-route to him, you get two power-ups: fire and tornado. Based on my death, I would suggest you use the latter rather than the former.
Cleared two levels of Jam Jungle then too, which is World 4. Looks like there are 120 levels to do, and I’ve done about 35 of them so far.