I wouldn't mind being part of an impromptu Capture the Flag event using the station as the playing field (engineers will have to modify it to add challenge).
We need flags.
Depending on # of teams, maybe 4 flags and a neutral find a hidden flag (RBGYW) and return it to your base can also be applied.
Medbay with a fast enough doctor can hide a flag and score a point easy. Just find a victim willing to take one for the team and have one stuffed inside them. Still technically a point since they would cross a line; but if the flag needs to be planted to count, then they'll need to be ripped open again to get it out.
EDIT:
Thinking it through a bit more, I think the R&R team would have it made provided the chef makes a (or enough) wheel(s) of cheese. Why? Cheese can be stuffed with all manners of things, including more wheels of cheese. Not to mention, a cheese wheel requires a tray or table to be sliced open and collect the goods within (buried under God knows how many cheese wedges you have to filter through, possibly making the server lag a tad to load up all the items (right-clicking) under that one tile, just to find a single flag under a metric crap-ton of cheese). Have fun scoring against the chef for that reason alone.
Chemistry can always rig their flag with proxy-space lube foam grenades (non-fatal rules applied), and relocate while defending with a bottle of lube in hand. Research can always have canisters of knockout gas surrounding their flags, unless someone wises up and puts on a mask before going through, but then they can always sic a slime or a mech after someone. Security can always plant their flag deep in the brig, and setup flashes and such beforehand, and always taze the opposing teams. Cargonia has the upper hand of having disposals on their side, but Engineering can always re-route the disposal pipes (but then again, Engineers are robust as fuck in regards to CTF (rerouting and so forth, plus boxing in their flag with reinforced walls; not to mention, the singulo area (especially with a live singulo; especially with an indestructible flag), or anywhere outside the station is downright unfair), so they're optional, and serve better as refs; same can be said about security).