Welcome to Puzzle World: excellent level, perhaps my favourite of all your levels so far, took me a while to figure out the trick I needed.
Scalding hot water: first part was simple and repetitive, but it took more thought than I expected to find a good method for the second part without running out of builders. In the end, though, my solution was a lot simpler than some of the things I had been trying

The level would look much better if you used the marble hatch and exit.
I like the tap-and-water object a lot; sometimes the lasers just don't have enough of that classic Lemmings feel to them.
Not enormously keen on the puzzle pieces. They work well in the Puzzle World level, but they're not versatile. Combining them wrongly, as you've done in your other level, looks odd. Maybe this is an argument for incorporating "special graphics" levels into Lix?
Mod Edit: Restored attachments.