I have noticed that there is no "action" tag present. There are some games that could be qualified as "action adventure" games, like "Elder Scrolls: Redguard" or the 16-bit version of Terminator 2, or just plain action games, like "Fallout: Brotherhood of Steel". I know that there are tags for sub-categories of the wider "action" genre, like "beat 'em up" or "side scrolling", but I was wondering if it would be worth it to have a more general "action" tag as well.
When there's a question about the plain action genre, then it'll make sense to create this tag. As I explain in my answer about genre tags in general, it's been an ineffective practice to try and "pair" these tags with their games on all instances. As such, we don't actively tag according to the genre that the game belongs to, and I suggest avoiding the practice in general. Do consider making an action game tag set on stackexchange.com, though.
Note that it may also be wise that, when such a scenario shows up, we try to fix up the name a bit better. I can easily see a tag called action being used to describe... anything. After all, when a very prominent measurement in certain popular games happens to be actions per minute... we already see this issue with health, just to name the most recent one.