Uploaded the WIP build to https://www.defold.com/community/projects/21328/ & http://adventure.tomires.eu 
I am getting abysmal performance in Chrome, which I believe is related to Render script's bad performance slows time
When tested in Firefox, Chrome, Edge and Safari, the performance was better, although Firefox refused to save my progress. Edge especially is getting fairly close to desktop builds in terms of performance, although I needed to allocate 2.5-3.0x more memory resources to the game when compared with native builds.
By the way, it would be awesome to have an option to run the game in full screen on the community pages. The default canvas is quite small for certain UI elements in our game.