As far as being a rage game goes, you've certainly got a bit going for being upsetting. As for being functional as a game, there's a few issues that I feel make it a bit less frustrating by design and more of frustrating by execution.
For example: The way the keys stick to one direction when using the keyboard make the movement feel pretty claustrophobic. When dealing with the moving ghosts, especially, I often felt like the reason that I wasn't getting past them at first wasn't because of my inability to time correctly but rather because I was getting faked out by stiff controls.
Another thing: certainly aspects of a game probably shouldn't be randomized. Going back to the ghost level, I managed to clear it by simply holding the Up key and running into my death over and over again until the randomization of their speed meant that my character ran right passed them. Took less than a minute.
The slimes level was also certainly frustrating because of execution. Making somebody perform pixel-perfect movements is a classic way to cause rage, but after examining that none of my character's visible pixels were on a collision course with a slime's visible pixels and I still got hit I understand why people think that this level is unbeatable. I can only imagine something like this is either due to a glitch or intentionally unclear collision masks, both of which are a death sentence for a rage game. If the game feels genuinely unbeatable then the response isn't going to be rage- it's going to be somebody unenthusiastically closing the game and moving on to the next one; especially so early on as the second level, when the player is nowhere near invested enough to want to see the whole game through.
Once I realized I couldn't trust the visible pixels to be an indication of collision masks I stopped playing, and it's a major reason why I'm not giving this what likely would have been at least 3 stars otherwise.
Keep making games! I can't wait to see what else you make moving forward.