No, the tabletop type rules are very integrated into the balance of this game. Stellar Crisis was different in the fact that everone did their turns simultaneously, and then the map was updated all at once. That strategy definately would not work with Massive Assault without destroying its sensitive balance.
Also, with the current setup, there are a couple traits that make turns long. When you start your turn, you have to check out the current situation and see what nastiness your oppenent has pulled off. You have to examine how to best fend off or chase down your enemy, then begin moving your units. That takes some time, as you attempt to direct your units to do the most effective damage. After that, you need to decide how to spend your money and which allies to disclose. All of that can be very time consuming, and makes it difficult to make a timed game work.
There is another way, however. Here's a proposal:
How about adding a game mode which acts differently: Instead of each player sending their move, then waiting for the opponent to be finished, they can stay in the map and watch the opponent.
That way they can plan their turn's strategy ahead of time, and monitor the progress of their opponent to see how long it will take before their turn. This saves a lot of time, as the watching player will have time to plan their overall strategy for the next turn. It also saves time in the fact that in the current setup you won't know when a opponent is done until you check your email or update from the server. Since I use web mail, and don't automatically see a notification when an opponent is done, sometimes it takes 5-10 minutes before I see that I have turns waiting. At least the game can be windowed, that is a great help

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Right now, with each player's turn taking around 10 minutes, and adding in the wait time in between, it can take 30+ minutes per full game round even if both players are currently online.
If this proposal was followed, each turn would only take like 15 minutes, as the players can plan most of their moves as they watch what their opponent does. This is if both players are being methodical. If both players are veterans, and are trying to get a quick game in, they can cut the turn time even more. So at this point we could put in a turn clock if the players desire. If they want a quick game, they can set the turn clock low. Sure, they'll make mistakes, but some people would prefer that if they can have a shorter game. Example: Chess. If you've played online at all, you've probably noticed that some people like to set a game clock as low as one minute. That leads to very interesting games

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In addition to a turn clock, there could also be a game clock as well. I can't think of an easy way off the top of my head to keep that fair though... I'll give it some thought.
The problem with setting turn clocks is how to enforce it. Do you set a specific time for each phase? How do we penalize a player if they're taking too long? If they just lose their turn, that might be too much. Losing one turn in Massive Assault probably would kill you.
All right, this could solve the time issue with multiplayer games, but what about dropped players?
Here's a possible solution for that:
How about having a list of currently open games. They would have the information about the players involved and the game settings. Then people can hop into any game they want. If you have players leaving, someone else can hop in their place. You'd have to penalize people for leaving somehow, though, because some people might just leave a game if they are doing too poorly. (I bet that happens with the current setup too).
These ideas might even make a multiplayer version almost palpable! Ok, maybe not 16 players
Heh, I've written a book. You asked for the ideas though! I know these ideas would probably take a lot of work to get in. I think they could make the game appeal more to the masses... See how many people play online chess, I'm sure a big chunk of those people would like this game if they only knew about it.