Huh, it's hard game. After tenth death I got myself comfortable with game and completed first two levels fast, but then there's third one which is really hard.
I think your game would benefit without runner mechanics, because if there so small time to react, it's hard to check both dimensions. And while first 2 levels is OK with it since they're mostly symmetrical, on the third one it doesn't go that well. So, as for me, without that time constraint third level might become more interesting, since player then will need to check on possible paths and think which one to take, while now I was just trying to go forward as fast as I could to avoid death by screen bound. Which ended just in another tenths of deaths, yea. Tho, maybe it's just me.
Anyway, kudos on completed jam.