The Galaga game will not play!

Steam-support eventually replied after four attempts to a query regarding this, saying, 'I must contact the developer'.

Steam Support gave to me a URL to contact the developer, here: https://gtm.you1.cn/helpsteam/wizard/HelpWithGameTechnicalIssue/?appid=403430
But when I tried to contact the developer, there are no buttons to contact them from the URL. It appears that only discussions are available.

Galaga is a superb favourite from the Golden age of arcade video games.
How can Steam sell games like Galaga, and then not provide support?

Is there anyone out there with a similar problem with Galaga?