• Overall: The game was really slick and the controls felt nice and precise.
• Fun: It was a lot of fun platform and grab the crystals
• Visuals (Graphics): Nice and clear with the simple shape art.  You could easily improve it with some Unity prost processing and 2D lights and shadows.  I like the level frames, maybe you could have the levels transition by having those metal arms on the sides of the frames push in new levels~
• User Interface: nice and clean!
• Audio: Some of the sounds peak in my head phones, you could normalize them more in Audacity, but they do the job well~

Keep it up! It's a great start to a puzzle game~ Please check out my game when you have time :D

Just tried this out! Fun little platformer. Felt the difficulty progression was fair and healthy!

Here is my feedback / suggestions down below!

Feedback

• I think the art is fine actually. Depending on where you want to take this game, potentially look at a game called Thomas Was Alone for adding some effects on squares n such :)
• I liked the sound effect feedback, so maybe more feedback on things like getting the crystal comes to mind. Some slowdown, and particles on important actions like crystal selection + death would be a potential addition.
• This might just be me being a little picky, but maybe consider finding a different sound for death? At the moment the sound is a bit harsh on my ears, along with the collection sound. The high frequency is a bit much for me.