This just came out for PC yesterday and I snatched it up right away because ever since I saw the QL for it on here I was super excited for it. My problem, I cannot for the life of me cannot for some reason beat 1-4. I have 2 hours logged in and just cannot beat it. :( I would say an hour and a half of that went to trying to beat this level. I know I'm not bad at video and played hard games before. I feel like sometimes when I press jump it just doesn't register, or there is just some sort of pattern I'm missing.  
 
Anyone have issues with this particular level or any of the early levels in the game?

Part of it could be you're not tapping the jump button (since if you hold it, you kind of float in mid air and can't get up stairs fast enough).
 
Also once you start sliding under the caterpillars you can let go of the slide button and prep for the stairs.
 
Really, though, it's a big issue about timing.

Timing.
 
It's all about timing.
 
Though I can't remember how 1-4 looks like anymore, just try to time your jumps a little bit sooner or later. After a while, you'll get it.
 
Also, you can pretty much just slide forever. Sliding won't prevent you from jumping and your hit box doesn't change. Not really a useful tip, just something to amuse yourself with.