I saw that, nice work!
Another suggestion I thought of, while trying to build an automated furnace, is it would be nice if the crowbar had a similar shift-drag function like the hammer so you can delete a straight line of pixels instead of just one at a time.
I also had some trouble figuring out how the logic gates are supposed to work (background in electrical engineering, so the concepts are familiar). Further descriptions for them would be a nice addition, but probably pretty low priority at this point.
Lastly, I noticed this while catching up on my chemistry, but I think you might have the chemical symbols for Potassium (K) and Phosphorus (P) mixed up. I think I noticed this with potash, in the game I believe it is P2CO3 but should be K2CO3? I could be wrong about this, but might be worth a check.
This is shaping up to be one of my more anticipated games in awhile, I will keep checking in now and then and provide feedback where I can!