I had gotten a single game where only two 90s spawned before that, but then one of them cloned again and I lost quickly. I think my strategy was pretty good though and it was just a matter of time til I got a win. But I'm guessing getting only one 90 was extremely lucky, and it definitely helped me win much faster.
For what it's worth I did have a lot of failed attempts! Most games end with a boss or two appearing in very bad spots for me and I just restart.
For anyone interested in how I did it, I took some screenshots. Spoilers below :)
turn 1:
http://imgur.com/9xdMpLLturn 4:
http://imgur.com/oMDLrAhturn 7:
http://imgur.com/YleY1Diturn 9:
http://imgur.com/pekKdmiturn 16:
http://imgur.com/bo7fHWhlast turn (24):
http://imgur.com/LIcn7Qu
Edited 6/20/2016 17:29:45