That was fun! Played it a bit while I was working and got to 1,000 coconuts per second before the game got too laggy to operate any more.
I am sure most issues are from the time limitations, but some things that would be nice to see:
-Monkeys become useless once you get enough helicopters and planes make helicopters a bit useless as well.
-Would be nice if later game you could place islands full of trees or something, was very tiring clicking T and playing trees after a bit
-Not require tab focus for the game to run, it would be nice if I could browse other tabs on my browser without the game pausing.
I really liked the concept for a clicker like this, let me know if you ever plan to keep developing, I'll stay tuned :).