Moving through jello: The walk speed (without picking up one of the vials) feels way to slow, the gravity is too weak and feels floaty as a result, you lose all you momentum basically instantly if you let go of the controls or press WASD while diving towards the ground, switching directions mid-action/mid-air feels rather hard and you seem to "hang" in the air in a way that doesn't feel good. You should also always be able to slide down a slope.
As for the timer, I think it moves down to quickly while you're using the grappling hook (is it tied to movement speed? it feels like it.). The times I have died 0.2 secs before hitting the next vial...
The easiest way to explain what I think is missing is to recommend you go play Bloodthief Demo by Blargis or even just Quake. That is what the movement should feel like and sometimes it does but often it simply does not.