I also noticed issues with the shader but I couldn't get the shader to look right without putting the directional light at an angle where it'd be impossible to tell a difference in elevation between platforms. I put color on some objects so it'd be easier to navigate levels 9 and 11 but I still agree that it's an issue.
I tried to do a 3rd person controller but I couldn't get it to work, even after following a 3rd person tutorial. I settled on first person because I found a really good tutorial for it on youtube. Yeah that issue with the Frog and Flying Frog was just an over sight by me. I never took that into consideration but it makes complete sense.
With the last three levels I can't deny that they are easy. Without the time to make more mechanics like moving platforms or obstacles it was tough coming up with new level ideas near the end. The thing is I had a schedule to get this game out before Saturday and I was behind on making the level designs so I got lazy with it. Level 11 took a long time to make and so I lost all energy to make Level 12. I agree with your last statement with giving the player every ability at the end but again, without other mechanics it was tough to make a level that only the Flying Lizard could beat comparative to the Flying Frog.
Thank you for the feedback!