Ah thank you I am humbled by your compliment. I love your design style too and have been following you for a little while :)
Getting the 2D character lit up was suprisingly difficult as I am used to using 2D+Animator+2D Lighting. With 3D I had to make the character in several pieces and attach them as a material to quad, using normals helps sell the effect.
I have fixed the Issue with the audio not repeating but honestly cant believe I forgot such a simple thing. lol
Yeah the error is because you clicked the exit button or pressed E at the end screen, this invokes 'Application.quit' which is meant for .exe files. I did not have the time to remove it at the time. I you saw the end screen then you completed it :)
On another playthrough I too experience longer delays between console errors and I will try to fix this and make them shorter intervals later today. Did you manage to find the hidden collectable though? they were there to help the inbetweens :D