Good game but a few problems:
1.I had a 6 on the I boxes which took me way too long to realize they were backwards, maybe add lines at the bottom.
2.Box physics, kept sliding off of them.
3.Moving the light is way too complicated
Some clever ideas here, I love the black light stuff. I agree with your critics and I would add:
!Spoilers! the multiple input of the code looks funny, but is not logical without any hint to it and there is only this one instance that it needs to be done.
Also I hate it when games don't allow me to put in a solution for a riddle if you have not done other steps, that are not related to the one riddle. Here it was the input of the morse code solution.
Regarding the light direction: yes a very annoying method, as lwrcs_v wrote, it's the degrees. 181 is basically away from the exit and 361 points on the exit. The up and down is best done with 361 and up in tens (371, 381, ...)