What is an STG? Searching online abbreviations only really got me "Swear To God" which seems unlikely in this context.

please add

https://steamcommunity.com/tradeoffer/new/?partner=83746743&token=G1uz-ZWc send trades!

Why is this game no longer available?

I downloaded Eventide Night just now and refuses to launch because there's no executable file. I did everything regarding integrity checks etc. This time I uninstalled and went to reinstall game only just now noticing it has 0b to install?! Did I just buy a false game or am I missing something? Any help would be appreciated....