I'm playing 2.2.1, and I've gone up to research the universal serum and I am researching man-portable particle beams. This appears to be the last tech on my list.
I haven't encountered and UFO's other than scouts, fighters, supply ships and harvesters.
Have I come to the end of the current version? Are there any "virus" related thing in this version?
I also sometimes get this scrolling black screen at the end of missions saying something like TODO: Script (something)