I was just thinking today that password-protected rooms could be another solution. Easier to implement, I imagine. The only downside is you couldn't make new friends.
Another fun idea: Transporter pods to board enemy ships?
Pretty good! I quit after dying at the end of the level with all the spikes. Level 4, maybe? The one after the dark level. Also, there was a bug that teleported me to that level before I hit the portal.