Thanks so much for the walkthrough! I see how you can do them both now. I'm going to try to work on a level that requires the ink trail so I can make use of the mechanic better. Also, I know about the bug I just haven't found a way to fix it yet.
I see that you've modified level 5 to force players to use the intended mechanic (I also got through the whole game without using it!)
Maybe you could adjust the inter-level message to better introduce the idea? I didn't realise that "Sending ink trails (X)" meant I could push crates along ink trails.
It's a really cool little game, hope you keep making them :)
I think you've made some changes since I first played it, but the only ones that now seem to force using that mechanic are the level that introduces it and 'Out of the way'. Even so, the puzzles are still super fun!
I hear ya on the limitations of puzzlescript text, but maybe something like 'Press X to push a crate along an ink trail' communicates the idea better?