When speaking about other universes people usually consider altered physical laws, while leaving logic and other basic things unchanged.
What if to consider other universes based not on different physics? Particularly, define a universe as a flow of qualia, thus considering universes with different flows of qualia? I think this expands the range of possible universes a lot.
Example: when you are sleeping you feel like living in a different universe, but that universe has no physical laws and totally different logic. Yet it generates a flow of qualia so can be considered quite an example of a universe (if it were not followed with awakening).
Universe where everything the observer believes true is true.
Universe where everything the observer wants happens.
Universe where everything the observer fears happens (consider here Warhammer universe with its Chaos zone).
Universe where everything the observer imagines happens (quite close to the world described in "The Chronicles of Amber" by Roger Zelazny)
Universe where there are only different smells and no space, form or geometry.
I think the sleeping dream universe is quite a strong case because it changes not only perceptive qualia but also reasoning qualia, altering the whole process of thinking.
Of course, if we define universe as a flow of qualia, the observer is necessary in every universe and he is unique in each universe.
What can be other possible universes based on qualia-based definition?
I also wonder whether the above examples are uncontroversial. Can a universe where everything the observer wants or believes exist? Can it lead to paradoxes?