Part narrative exploration of written accounts of psychedelic experiences (what I expected going in), part polemic, part advocacy and part education. I suspect that for the message to truly resonate as intended a very specific worldview and cultural context is necessary (contrary to its universalist presentation), so its ideal audience is rather small. It's unlikely to change any minds and, to someone whose worldview only partially overlaps with that presented, its content ranged from the insightful, through the obvious, through the totally backwards and through some unfortunate patches of thin nonsense.
However that does not ruin any experience, there's beauty in it and some valuable messages. Even if you are not fully aligned with the worldview espoused of psychedelics as an gateway to the external and spiritual more than the internal and obscure, as I am not, there are things to appreciate or learn from this and I would recommend a watch. Parts will need discarded but other parts are of great value.
My lukewarm rating comes primarily not from my disagreements in spiritual worldview but from a sense that the components of the film work against each other. The narrative exploration is undercut by long discussion segments that veer off far from the texts. The education is undercut by needing to make room for other content, for example setting is often mentioned but not elaborated on in depth. The advocacy of drug liberalisation, a cause I support, is built on twin justifications of (sadly underexplored) medical merits of psychedelics and of laying out a spiritual faith-based view of reality as revealed by psychedelics. Naturally these do not complement each other and, indeed, undermine each other. This film is effectively several other potential films crowding each other out and stunting what they could have been. A shame, but take from it what you can, and enjoy the process of doing so.