A bit easy
The game got kind of monotonous after a bit because it never picked up. The speed never increased, the obstacles never really got in the way, etc. The most dangerous thing was using the abilities, because they had a tendency of launching you prone into the air when they ran out, making it a crapshoot as to whether or not you land on a building. This was a particular issue with Harry. It would have been nice if the player had a grace period where they could manually deactivate the abilities so they could land where they wanted to.
The idea was interesting, but the powers didn't feel varied beyond aesthetics. Jaws and Harry played the same way, Jacob played the same way as the normal character. I understand the time constraints, but I still feel the game needed more substance to be really fun. If, for example, turning into Harry turned the game into a bullet-dodging sort of deal where you could defeat enemies and collect pickups to prolong the duration of the ability or it was shortened by colliding with things, it would extend gameplay value for me. Again, I understand that there were time constraints, but from my (admittedly limited) experience with Flash, that doesn't take too long to do.
Overall, it wasn't a bad game, but it just lacked content and difficulty for me.