short ver:
i think this game is impossible in its current state,
possible fixes: make monster slower, increase stamina
and/or
slow the speed at which stamina decreases
+
have you completed this game, even once? or if not, have you at least gotten to 600m left?
long ver:
alright, where do i begin:
I barely made it to 800m left. I think the game is (at its current state) impossible.
The mouth gets to the player faster than Disney canceled The Owl House.
And your stamina doesn't help with that, as it too lasts as long as a season 1 RWBY episode.
I found this game by chance while looking for games to speedrun,
(I look for indie games to upload to Speedrun.com for exposure.)
I think if you either increase stamina to 200 / make it go down slower
or
Make the mouth thing slower
maybe even
Make the mouth thing slower but exponentially go faster as does your speed.
But for the time being,
I think this game is, currently, impossible.
But here's a question just in case:
Have you completed this game, even just once?
By that I mean have you finished the full 1000m? How long did it take?
If not, have you at least gotten to 600m?
Sorry for the long comment.