Nice game entry! Enjoyed playing it, but I guess it still could be a bit easier regarding the increasing difficulty.
A few small things:
- it would be nice to “regain” a bit of the money you spend at the previous island
- a slight variation of the sharks would make a big difference (e.g. small (weak) and big (strong sharks)
- also some variation in weapons or so
- add a finish overlay
- and add some ambient stuff (wind, birds, a bit of variation in the water shader)
All in all, really nice game!