Honestly, a very interesting concept for a mini-game! I enjoyed playing it once I figured it out, and managed to finish it after like 5 attempts!
However, I gotta nitpick the "figure out" part. I feel like the concept could be presented in a better way. My first two attempts I've spent trying to understand the controls, mostly because nothing communicated to me that I had to merge 3 or more (is it like a norm in tile-matching games? haven't played that much titles in this genre)
Additionally, I didn't spot any difference between different types of hexes. It would be interesting if there were special types of ghosts who'd react to certain hexes more, forcing you to prioritize some columns instead of just trying to maximize any of them. Imagine a scenario where you'd have a wave of yellow and cyan ghosts, and you could either get a spell of both red and blue or realize they both share green and just use that. Definitely a potential here!
Speaking of cool things, I think hexes having resets based on usage instead of time would be more engaging - at the very least, one less thing out of player's control 👀
Despite the lacks in gameplay I mentioned, very cool idea, and still quite solid execution for a jam! Good job!