I have a soft spot for 2.5D games, so this immediately caught my attention :) I really like how the 2D characters sit inside the 3D environment — it feels natural rather than like two separate styles being layered together. The character designs are really charming too, and the voice acting gives them a lot of personality.
The only real issue I ran into was with some objects getting stuck and blocking my movement, which forced me to restart a couple of times. But overall, I really liked how you pulled this style off.