thank you! that helps a lot. my thoughts on the rest of the levels:

#3 - the timing of opening the gates is so brutal... otherwise neat1
#4 - I liked this! straightforward but still requires some thinking to prevent getting stuck.
#5 - my favourite level, the different approaches to counter-intuitive puzzle sections is nice. that said, I did not even try twice with the parts with the ants. the timing is too tight for me.
#6 - a nice way to end the set :) if only I could tell what the farewell message is...

also I looked at the gif (I wish I could pause and resume it !), and I can't believe I forgot that keys stack... a big part of my frustration in level was I kept going back to the doors at the end with a red key every time I picked it up. perhaps I've been so used to playing zzt lately that I assume every game works like zzt, with only one of each type of key being held at once...

- nikki