Defense Missions, Some Ideas.

[Nagisawa]

OK, for those of us who either solo primarily, or can't get a full team, would it be possible to have turrets on a timer at various spots, that you'd have to run and activate?

 

Have them destructible as well, so you'll have to run and maintain them.  A click to reactivate/fix.  Or if you're feeling badass enough you can completely ignore them and just wail on all the waves with your uber frame and serious skills (and I'm serious, you had to be GOOD to be able to solo one of these past the first five levels, originally as in U8, for the first few planets.)