I can see what you mean from feeling like holding would be better to build up speed. In my mind I thought of kicking to get up higher in a swing with the impulse sort of pushes. But it's been very interesting to see that it wasn't intuitive to everyone and I've been trying to wrack my brain to think of ways to explain that through gameplay.
Sorry about the scaling of the external player! I mostly tested in windowed mode or on the webplayer and added external as a second thought. But thank you for the feedback! I'll take more care in future projects