Ghosty's character design is SO cute, and I love both the music and the speech sound effects.
I like the idea of the gameplay, and I like being able to see the paths of my previous lives instead of just the boxes they hit. However, there's a few flaws in the execution of the levels and mechanics.
The first 6 levels are pretty straightforward. Around level 5, it was getting stale and I didn't want to continue playing. However, the simple addition of the moving edges in level 7 did so much to revitalize my interest in the game. The double jump mechanic introduced in level 8 did the same thing. Suddenly the game felt like it required skill instead of lucky guessing. One-sided platforms like in level 10 added more interest. I think these things should have been added earlier.
I like the double-jump idea, but with it several frustrations were introduced. First, the way Ghosty accelerates when he jumps makes the double jumping feel extremely inconsistent. As I spent more time failing the same double jumps, it was frustrating to finally clear them and then have to complete a lengthy level by guessing where the remaining blocks were. Another issue is that after being on a level for a while, some of my ghosts stopped showing blocks I had previously hit. These three issues together meant that by level 10, my gameplay experience looked like this:
I fail the same difficult jumps multiple times. I finally pass it. Then, I run into a block I've already hit before but my ghost stopped showing it to me OR I have to start the trial and error process of dodging unseen blocks. I hit one, and restart the process.
I kept playing because I wanted to get Ghosty to thier party, but ultimately I had to quit at level 10 and watch a playthrough someone else had posted. After putting so much effort in, I was disappointed to find out that there was only a vacuum waiting for him.
Overall, the game has a simple but good core idea. With some cleaning up, mechanical fixes, and variety earlier on, it'd be a much more enjoyable game.
Edit: I forgot to mention that the camera moving up and down to follow Ghosty was a little disorienting. Since both edges stay in the screen's view the whole time, I don't think the camera needs to move at all!