The amount of content you made for this game, especially considering you came in late, is really amazing. The shader looked really cool, and the fact that you had time to even make a cutscene is something I don't see a lot in game jams.
However, I didn't care much for the gameplay itself. I found the "press button to select item, then press different arrow to place it" to be really hard to quickly grasp, especially since they were so closely aligned at the bottom (making it feel like pressing that button would place that block in a Coulomb automatically). The inconsistency of the bombs were also really annoying, especially because it was hard to properly account for the risk of the bombs carried by, say, building a section of frowny faces you'd want to get rid of. Finally, I felt the game had too long of a time between 'cash-out' points where I could clear the board and get the points I've built up. Too many times I would be leisurely placing blocks only to run out of time, or I would rush, get a bomb, and wipe out half of my progress. Either way, the end result was the same: I ended the game with a score of zero. I know you designed parts of it to be purposefully annoying, but I think you went a bit too far with it.
Also, personally, I would have made the happy faces white with black outlines and the frowny faces black with white outlines, just to make it easier to differentiate them at a quick glance.