EDIT: I created a new submission  for it, should someone want to discuss it.
I confirmed that it compiles within the Arduino IDE. Porting it to another micro shouldn't be prohibitive. The amount of Arduino specific stuff seems to be minimal.
the espruino js lib is in the making for esp32
However it doesn't include bindings to your device SDK, e.g. timers, gpio etc.
We didn't port the whole Mongoose IoT FW to esp32 yet.
The Mongoose IoT FW includes other things such as a configuration system (via serial or http), mdns discovery, full OTA, and a few fixes against the base espressif SDK that improve network reliability, fix libc bugs, replace the malloc allocator to reduce fragmentation etc.