Stackoverflow model disallow user from creating tags belove some quite high reputation level. But this particular site really need specific tags for more or less popular games. I would like to propose to introduce some tags proposing mechanism, because right now there are so many untagged questions and this number will be just rising.
This is by design, and is unlikely to be implemented.
Less popular game tags can be saved by users with even zero reputation by asking a question about the same game that currently has an untagged status. Feel free to take up the mantle, just note in the question that it needs retagging, and please link to the other question about the same game so the tag isn't purged in 6 months.
I think this is a reasonable concern. It seems likely to me that a new user will have a question about a game for which there is no tag, and may struggle to find the untagged tag.
Incidentally Arqade (the gaming stack exchange site) has got the auto-deletion of single use tags turned off: https://gaming.meta.stackexchange.com/q/5379/3958