Spam drop them in the early levels where there aren't so much things. Chances are, you will get 30-40 before the UFO...then when it does come, try to get it to 50 with as much lives as you can. When the MONSTER goes red mode, you can easily get 50-ish right there if you start off right [if you start off wrong, you'll die really, really fast lol]
xD
It takes a bit to load even the 'intro' screen, so just wait if you're seeing a black screen. At first I thoguth I had loading problems too, but when I went off to do something quick and came back, it was loaded =)
 "Tactical Assassin Substratum"){kind=icon}
 "Talesworth Arena: Death Watch"){kind=icon}
 "Kaleidoscope Reef"){kind=icon}
 "Parachute Retrospect"){kind=icon}
 "Kongai"){kind=icon}