I had an idea for a tricky challenge: An avian (bird) that is as "light as a feather!" Their pieces will be lighter, and tend to bounce a bit more, making it a little harder to keep and set up combos.
For their lore, I imagine that they are part of the delivery service, specifically an air-delivery specialist. Requesting air delivery service adds a premium charge to normal orders, but the premium is still affordable! It adds to the tip, as well! ♫ Want your treats fast, even though you are far from the shop? Call your bird friend to get those treats to you at near-Mach speed!
Alternatively, if it comes to a more hyper avian (bird), they can still deliver, in spite of their added size. ♥ They decide that they get larger during the rainy days. Certainly going to be "heavy rain!" The harder it storms, the larger our bird friend gets! Their puzzles will be similar to Azura's Texas Special game, but with that same, bouncy trickiness from before.
What do you think?