In GE64 SP the player sometimes has to search for keycards/keys and search for the characters that have them.
Why not turn this into a MP game mode, especially because this, errrr... 'mechanic' is not involved in the MP and thus GE:S.
The mode would go a little some' like this:
There are two teams. Nobody can decide what team they want to play on so the teams will be automatically balanced.
At the start of each round, each team will have as many keycards as the amount of player of the team that has the least amount of players. (So when 13 people are at the start of a new round, you will have one team of 6 players and one team of 7 player. Each team will get 6 keycards.) Then the amount of keycards will be automatically handed out to each player of a team. (So when the round starts, each of the 6 players of the second team will get a keycard and the 7th player won't).
Time to start the round. The objective for your team is to get all the keycards. If your team has all the keycards, your team wins the round.
In order for a player to steal away a keycard from the opposite team, a player has to track down the person who has the keycard (radar?) and kill him.
Once a keycard holding player is killed, his or her keycard will be dropped (more like thrown in the air to a random spot around the killed player, like in GE64) and the player has to grab the key.
Obviously the player who has the most keycards will become the primary traget of the opposite team... simply because then you can instantly aquire a lot of keys with just one kill.
When a player with multiple keycards is killed, his/her keys will all the dropped a meter or so away from him/her and will be scattered. That means that somebody could grab the keys fast and run away, but become an easy target for the opposite team who want their revange. But you could ofcourse also work together as a team and have multiple players grab the cards, so that they are harder to recollect by the opposite team. So that makes cooporative play rewarding and better skilled teams better.
But when your team has their cards scattered, you cannot all jump onto a single keycard holding player of the opposite team because then only one player has to grab an explosive and everybody will be dead and all keys will be scattered but close to each other for the opposite team to pick up.
So it depends heavily on team play and tactics.