The controls don't feel very responsive making it hard to play especially since it is so easy to die and it seems like everything has to be super precise in order to win the level. For example, I would sometimes jump and barely make it to land on a platform and other it would barely get to half way up the platform. Also, the hint system is good but it should stop the gameplay as it blocks you from seeing what is happening and I died a few times because I was in the middle of jump when it pop up and could not see the bullet. lol
Now that we are past that, the game has some fun ideas that make it stand out from a traditional platformer (it took me a while to remember I could shoot the goo so the first level I beat it by using the shield the create a gap in the crates that I then squeezed through it) - lol . But once I started shooting good and could capture my enemies then I got the theme.
I think if you work on making the controls tighter and the timing a little more favorable for the player this is would be an even better experience. Nicely done