Very Interesting! Tho first play when I press Z it does not progress the dialogues, so I retry once more it finally goes through. I like the empty sprite become pebbles, it caught me off guard hahaha
At the final place when I met the blue guy, I roll downwards, wonder if the void has anything there. LOL
I am curious so I let the pebble roll for 5 minutes I guess.
Thanks for awakening my curiosity on finding hidden easter eggs!