Like mentioned below, it appears you left viewport scaled to actual size. I was able to play by zooming in my browser window.
I think some instructions would be helpful. I had trouble figuring out the mechanic initially. What I came up with was it appears you "drop" pollen when you move/jump. I had originally just assumed the pink particles were just effect to add some flare to your movement. After some testing, the more of the particles I drop by moving I do see my gauge deplete. It's an interesting mechanic because you now have to use your movement carefully and with consideration, else you wont have enough pollen to complete the stage. A fun little platforming/puzzler hybrid. However, you can't seem to "jump" while on top of the flowers (I'm guessing because you fail the "on ground" check required to jump) and I couldn't seem to find a key that allowed you to just "drop" pollen. So if my initial jump on to the flower didn't leave enough pollen, I'd have to walk off and then jump on again. This isn't necessarily bad, but felt clunky. The mushrooms seemed to react to me pressing the up key, but not always. I like the look and feel of the game. Definitely consider continuing to tweak the mechanic while maybe working on communicating what that mechanic is to the player.