* No standard library included (separate micropython-lib)
* No reference counting
* Simplified object model (basic {{{__new__}}}, different MRO, no metaclasses)
* No descriptors (some optional support)
* Docstrings removed, limited introspection
* No locals()
* Limited unicode support
* No {{{__del__}}}
* Simplified {{{async}}} and {{{await}}}
* Optional {{{__dict__}}} and read-only
* Low recursion limit
* Slice assignment not fully implemented yet