The controls are simply unrealistically difficult.
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Well, thanks for playing, anyway. I definitely intended for the controls to be difficult so you had to focus on the actual mechanics of running away, and to replicate that feeling of trying to run from something in a nightmare and not being able to. (Hence the inspiration from the game QWOP.) Funnily enough, someone else in the comments said he thought maybe the controls were too easy. It's hard to nail it for everyone.