Hey, it's great to see this come back! Through a combination of a charmingly goofy world and characters, a challenging escalation of puzzle difficulty through the introduction of neat mechanics like boss blocks, and intermission stages which help me remember all of the subtle intricacies of your moveset, it all sums up to create a wonderful adventure! Some great craftsmanship on display here in general, and I especially enjoyed learning how to make the most of the moveset despite how challenging it was for me to master!
That said, as much as I enjoyed my time, I did have some issues with the design here and there:
*You'll call me stupid, but I took a long time before I realized that the goal of each match was to delete all of the robots from the board. I would just keep making matches and assume I was dealing damage to the dropper with each match, or was building up to some sort of score threshold, or just needed to survive for a certain amount of time. Finally my brain made the connection after some time, haha! I wonder if there would be a way to make that more obvious, like a counter on the HUD telling you how many enemies are left.
*Speaking of the HUD, I do wish the game had a bit more information to give to the player. For example, a little preview of the next block would be nice and would let you plan ahead. It's also a bit of a bummer that there is no score tracker: would be great if you could see how well you did with some sort of grade after beating a stage. It'd also just help add a bit of pizazz to the game.
*Considering puzzle games are usually quite juicy and animated to make things exciting, I was a bit disappointed how dry this game is. You could argue it's superficial, but consider this: taking the effort to try and make a big match like 4 or 5 in a row, or setting up and pulling off a combo, only for the game to not give any sort of positive feedback to differentiate it, is quite demotivating and makes me as a player only want to do the bare minimum.
*I'd get annoyed when I'm standing right below the block dropper, ready to intercept whatever it drops, only for it to insta-teleport to another position right when it drops. I really feel like the dropper should smoothly move into its next position right after dropping something and stay there to serve as a preview of what's coming next. It would make things feel more fair and let you strategize.
*Some mechanics were a bit unclear, particularly the way to damage bosses. I kept trying to blow up bombs next to them, only to realize they have to 'lead into' the boss to actually cause damage. Feels like an unnecessary complication, and the way bombs blow up simultaneously instead of one-by-one towards a direction doesn't help make it intuitive.
Despite that big wall of text of issues, though, I had a grand ol' time!
EDIT: Whew, still working myself through story mode. It's probably because I'm a puzzle noob, but damn if those fights on the train and the doublecross were really exciting and challenging!