advertising – Web Page Interstitial Ads – At a Set Moment In A Game

I have nearly finished a web page which is a real-time game (ie not turn based).

It has divs which are shown or hidden through the course of the user experience. So any adds in these divs will be hidden at times, which may be important for possible rule breaches.

There is one point in the game (when a full-screen canvas div is shown) where there is a pause which would be the perfect point in time to show an advert. It would be nice to show an Interstitial Advert (not a popup) and then return to the action.

Is this possible on a normal webpage? How can it be done? Which advert people (eg Admob) do this?

Additionally, I might like to give the player an option of seeing the advert prior to the game-proper actually starting, or see the advert within the game itself when this pause in the action takes place. Ie, give them the choice. Have a pop-up saying something like ‘See advert now or in game?’ Please note, the advert would not be shown at page load. It would only happen when the players start the real-time action segment of the game.

I want there to be only one advert per game maximum. (A game takes about 10 to 15 minutes.)

Or even do some form of Reward Advert, that allows them to have a whole hour of gaming fun without adverts, but only after they view a Reward Advert. Maybe get some in game bonuses for that hour as well.

Is that possible on a normal web page? How can it be done? Which advertisers do this?

If none of the above can be done, how would I work it so I could do banner adverts on some of the divs that do not have to maintain a high frame rate, but ensure when the Full Screen Canvas div is shown requiring a high frame rate, no adverts are shown and will not load in the background?

Please note, the webpage is written so the divs are shown and hidden throughout the game. It is not a normal webpage where you go between multple html pages. This means some divs (with adverts on them) will be hidden at certain points in the game. Is that allowed?