Very cool and original mechanic! I've never quite seen an on-the-fly gun builder pipe system like that. The demo does a good job of showing some of the different possibilities/ideas. (The door at the end requiring the absorb-spamming).
I found that the near-infinite range of the gun seemed very OP though haha. It was very easy to stay away from danger when the basic shoot has so much range.
Just an idea inspired from playing... maybe you could have a sort of 'catalyst relay' where once the water in the pipe goes through it, that would charge-up or alter the next shot/absorb. One of those 'catalyst/relays/augmenters' could increase range?
Anyways, love the demo, it's already inspiring ideas in my head! Thanks for sharing.