I read the reviews that mention pacing, and you said you tried making it faster but it didn't work.
Honestly just abrupt scene cuts would do fine.
Squirtle spit out his tongue too long, you could cut that by a second or two. Prof's creepy lavender town staring could've been cut after the first "Uh...professor?" dialogue line.
Example:
*Prof staring into space with music playing*
"..Uhh..professor?"
*camera switches to the Prof. The music cuts off suddenly, and the background behind him returns to normal. Prof. Continues staring for a split second before saying...*
"Wha- OH! Nothing, don't worry about it!"
*Flash returns as usual*
MUCH cleaner and retains the audience's attention.
As for not giving you a full 3 stars...the end was just too cruel to me for it to be funny or amusing. I just left feeling depressed and sad, which is OK for serious flashes but not in something I was expecting to be funny. So when it just became horribly inhumane my opinion toward the flash lowered.