It's been mentioned, but my inventory got bugged. I was playing as a wizard, and two of my spell slots became unusable because they appeared to be empty cells, but were in fact filled with spells I had destroyed. Perhaps this would be fixed if you made items switch places when you dragged an item to a non-empty cell?
Hold shift to delete metal or draw P silicon. I too wish this had a better tutorial, because this is something I want to learn about and this would be a good way to get rudimentary knowledge as a starting point. Refer to NotJack's top rated comment for very important information. And refer to wikipedia's articles on boolean operators and logic gates to find out more clearly what your objective is.
CrossCrossCross: There is a small ledge that you must land on using the speed powerup. From there the final jump up should be easy enough with 3 jumps -- if you have enough time left! HURRY!
 "Cardinal Quest"){kind=icon}
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 "A Game About Game Literacy"){kind=icon}