Looks like fun!

x An infinitely complex clockwork labyrinth where time has no meaning. It's possible to solve the labyrinth in such a way that you emerge in the far future or distant past.
x A great city-world where humans reign as supreme as they do in most other campaign settings, but this time they are far crueler and more tyrannical about it. All other natural and supernatural entities live in fear of being enslaved or even consumed...
x A cosmic amoeba; various organelles correspond to cities/planets of other planes; ships travel at interstellar speeds through the cytoplasm (instead of vacuum) from vacuole to vacuole. In spite of it's alien/Far Realm nature the amoeba is entirely benevolent and everything radiates Goodness.
x The forge of creation; blinding radiance and thunderous noise everywhere to the point that any visitor is blinded and terrified, but when they escape they discover they've been de-aged to the prime of their lives once again and all their wounds have healed.
x The end of time (or the beginning) - a quiet planet where gentle breezes shift the silver-white dunes of the desert, perpetual moonlit night, black oceans reflecting the moon and stars, benign skeletal undead sitting on the shores quietly contemplating philosophy with all the time in the world. Unlike the next entry entropy has stopped due to the serene natures of these undead and their idyllic universe will survive indefinitely. They are friendly and sagacious with all visitors.
x A parallel universe of the above - a collapsing midnight red-black universe where even the youngest stars have all long since become red giants, populated by malevolent incorporeal undead, the pinnacle spellcasting civilization who all became wraiths and intend to drain the life-force of other universes to rejuvenate their own (and they've done it successfully many, many times...)
x The wish dimension. Anyone here can effectively use wish at will (and not at will, since even subconscious desires manifest); this can be frightening but ultimately no one can be harmed as the entire plane was artificially constructed by an ancient race/deity and safeguards were included. People leave with epiphanies (xp or equivalent) about themselves , assuming they want to leave.