Thank you, everyone, for your kind words.
Ithaquatini: The card mechanism is pretty straightforward and is largely poached from that used in many of the games produced by the 'Too Fat Lardies' (i.e. 'Sharp Practice', 'Through the Mud and the Blood', etc.).
Basically each 'team' on both the Lurker and Threshold sides is assigned an Activation Card. When I say 'team' it can mean full Threshold teams, sub-groups or even individual models in some cases - the choice is yours based on the scenario. The Activation Cards are all shuffled together thereby making sure every turn's series of activations will be random. Once a team has their card drawn they can perform their Actions as per the rules.
I also include into the deck a single 'kill switch' card that I've called 'The Stars are Right'. This card will bring the turn to a sudden conclusion even if there are still cards left to be drawn, BUT it allows all those 'teams' whose cards have not been drawn to select one model to perform 1 single Action. This single action cannot involve shooting or melee actions. This way the system adds a bit of tension but allows players to do something even if they've had the bad luck of not having their team activated for their full 2 Actions through the normal card draw.
One thing to remember if using this system: You have to initially create the deck so both sides have a fairly equivalent number of cards otherwise you risk a situation where one side is dominating the deck. Once a team is eliminated their card is removed from the deck.
The reason I use the card mechanism is that if you lump all the players' teams into just two basic 'sides' what often happens is that one player will do most of the activations (due to their proximity to the action, the mission goals, etc.) while the other(s) are left in the cold (as you only get 1 model Activation per side). The use of cards does make for longer turns (and increased mayhem) but they allow everyone the chance to get in on the fun.
I encourage you to try it out and see what you think! We've used this kind of system quite a bit and it always gives a good (if unpredictable and bloody) game.
Regards,
Curt