If My Body is a Cage has one flaw, it is that it certainly expects the GM to be familiar with the conventions of  TTRPGs.   By assuming the GM is experienced, the game's book is able to massively save on page count by not providing generic explanations of concepts.   

Many rules are not fully fleshed out and intentionally left in a vague manner to encourage table rulings.   Rather than a weakness, this contributes to the symbolism of the game.   My Body is a Cage is about dreams and dreams often don't make sense or only provided partial detail with your brain madly trying to add context in order for the "dream logic" to work.  

Much of the background material focuses on the drudgery of failed lives and lost dreams but the included adventures themselves include a wide mix of styles from horrific to bizarre and some material that is downright goofy.   My Body is a Cage then is at once a game that can be deeply emotionally challenging or hilariously bizarre.   By having the dungeons occur in dreams, the GM is free to introduce virtually any style of story they might wish, leaving the game particularly flexible if a table is looking for something to tell a wide variety of stories with. 

My Body is a Cage rewards character flaws with tangible benefits and encourages players to make risky decisions that are likely to fail and bring along all the ramifications of failure.   From a player perspective, this is a great title for newer players who might not yet see the fun that can be had in failure.   Veteran GMs who are looking for a freeform title or have newer players will find this game very robust and entertaining.  Newer GMs might find the game tremendously challenging as it intentionally leaves in tons of blanks that you'll have to fill in on your own.

The book itself is beautiful and a masterclass in physical media design.  I regret very much that I only have the PDF but I enjoyed flipping through the pages very much.