In short it's a fan-made custom battle encounter with Tomoko aka anime character from Watamote in Undertale style.
It won't let me play, it just stays on the loading screen that says 'powered by construct 2'. Can anyone help?
Well you're not mising much but in case you still would like to try this game i suggest you launching it with a different browser(Google Chrome for example) sorry for this lackluster suggestion, can't troubleshoot this case as it works fine on my end