Thanks for the feedback!
I'm definitely still working on some more obstacles. Right now the level generation is completely random, but I also felt something was missing. Your suggestion to make more difficult obstacles appear after a certain score is also one of the solutions I'm toying with. I still have a ways to go, but I hope I can turn it into a fun game in the end :)
[EDIT:] I forgot to reply to some of your "questions" in the video. First, you've played a very early build, the most recent one already has a lot more variation in the levels. And yes, the heartbeat is just there to light the environment for you. The closer the enemy is, the faster it beats and the more you see. But it also means the monster can grab you if you make a mistake... I hope it creates interesting gameplay where you decide to wait for another heartbeat, or just jump in the dark.