very straightforward and easy to learn, but fun!
I liked how you provided some feedback to let me know the speed was increasing, and it was good that the difficulty increases.
I did have a glitch in one of my games where it stopped getting hard - it kept spawning only one obstacle per screen, always the same height, and this went on for a couple min before I quit out.
It might be nice to somehow control how high you jump, but still not allow infinite jumps. Maybe based upon how long the space bar is held? or maybe give a double jump? Some way that I could come down more quickly when I didn't want to be in the air that long. Just a thought.
The game was very responsive - I felt very in control of when the jump occurred and I liked that.
A little background track might be nice - what does Kalak like to listen to when he runs?