Very nice looking how-to-play screen. I'm glad you included that to ease me into it. The color palette was really nice too. Everything popped, and the stage looked very pretty. Good job on the models as well; they were really well done. The boss was absolutely horrifying and a thing of nightmares. I'm convinced that thing is an eater of dreams lol.
Also, great job implementing variable jump height and getting the shrink mechanic working. For a first game made in UE5 Blueprints, this is genuinely impressive. There's a lot of potential here, and it's cool seeing an artist-turned-dev start putting these ideas together.