I've played 2 games via powerpoint and gmail chat. The games look something like this:
I take my turn, moving the objects that are the cards (all to the correct scale), and drawing arrows for the shooting where needed. I send him the power point file, he opens up we resolve the combats, he marks damages, flips cards around when they run (and do those smashing arrows) then does the "X" if they died for one reason or another. then takes his turn. Copying the slide to a new one and making the changes. I roll dice on my end, he rolls dice on his end. Snarky comments ensue. Lather, Rinse, Repeat.
So, a 2000 point game which normally would take no more than 1.5 hours takes 3-4 (usually over 2 evenings)... but I ask the question, does this count as a game? :)