Huh.. other than the deer I don't see any that can be consider "annoying fast" (unless you are going for a perfect "score")
You are expected to take some hit, as I consider getting knocked back as part of the game.
(during development time they are even faster, I have to re-adjust their speed many times)
(the bird are quite fast so I only place one, and also they don't chase you forever)
Anyway that's something to consider (to make a level where you can get away completely unscathed).