So since I beat my Doubles time record at the Trainer Tower by quite a lot a couple of days ago, I figured I'd try to do the same for the other modes as well. Today, I played through the Single battle mode, where my record was 18 minutes. My Gengar was my lead for most of the battles, and it did pretty well overall. The only trouble it had was against his Beedrill that used Double Team and made Gengar miss several turns in a row. I also used my Rhydon a lot as its attacks came in handy, though it would've been more useful if it wasn't so freaking slow.
Anyway, I made it to the top with a time of 12:xx, so about six minutes faster than before. Will try getting faster times on the other two modes sometime soon, probably next week.