Cops vs Robbers mode and some other ideas
A mode where the guards need to chase down the intruders who have the case and need to reach an extract. The intruders spawn a little closer to the extract, but taking the fastest path there will most likely get them killed. There could also be cars which I think could be done like a game called subrosa does it. Also moving maps with moving cars like Train Heist are pretty cool and I think add a lot to the game.