I loved this idea! I spent a long time on the first puzzle and didn't get it. I think that this idea has a lot of potential, especially if you find a way to smooth out the difficulty curve. For example, I think that you could easily break the first puzzle down into three: 1-two boxes, one target, one digit; 2-two boxes, one target, two digits; 3-two boxes,two targets, two digits.
Viewing post in XX Steps jam comments
Thanks for the detailed feedback! This is actually just a single-level game. I got caught up with other things when the jam started, so by the time I began working on it, I was pretty short on time — the actual development time was about one day plus one night.
So yeah… the difficulty curve ended up a bit cursed. I might update a post-jam version with more preparatory levels like you suggested!