Quoted from Jgaltr56:And and along those lines, having balls stored normally in various places around the playfield in front of a kicker instead of a only in a trough would be necessary and pretty cool. STTNG and TZ does this to some extent. Probably too late to implement in Alien if not already there but I give permission for this idea to be used in a future game.
I LOVE the idea of an unexpected added ball. I think using a couple of scoops, that will get loaded as a course of play, but not immediately returned could be an interesting solution. Could ramp up tension as well, since you know its not going to fire until sometime after you load it, but you just wont know when.