Thanks a bunch! The red triangles restore your health, but it's only obvious once you spotted your triangle goes darker to show your health - I went minimalist with the UI.
Agree - the speed boost definitely only make things harder, but it's somewhat hard to resist going through them :) I must admit I didn't have a lot of time to balance the game as I crammed the jam in one evening, so tweaked until it felt fun and moved on to polish things off. Room for improvement!