The Wall has started to prove that game shows can be viable during primetime on a big network, if they have an interesting gimmick that really draws people in.
Then again, The Wall might just be successful because it has a unique premise.
There was a time when there were a ton of game shows dominating on television, but in the more recent past, game shows on network TV have mostly been the syndicated classics that air prior to primetime, like Wheel of Fortune or Jeopardy!.
Since reality competition shows are slowing down in terms of popularity, having a few game shows should be an easy–and cheap–way for the networks to continue to draw in viewers.