Game developing in jsge is similar to popular engines: you have create you game pages extending ScreenPage class, register them in the app, import assets and tilemap using assetsLoader and then start the page rendering. More information and tutorials here
Rendering under the hood has done with webgl1. It is quit fast for browser and mobile, cutting everything off-screen allows to use huge maps.
There is no physics engine, but boundaries and collision detection is included. In my case it is useful for creating top down games.
Any feedback is appreciated! Thank you!