Wow... I've heard of this game. On YouTube. Man have I got a treat for you guys.
Apparently, there's this guy who's actually removed the limit on the breast size gauge, allowing him to make the breasts absolutely enormous. He's posted many of his Oppai Slider videos on YouTube. I'll link to a good one right now called "Lume and Her Expanding Breasts".
http://youtube.com/watch?v=2BNUXTwn6po
And what's great about the clip is that the guy actually uses the guage to make the breasts bigger, so you get ACTUAL BE PROCESS. You can also get a hint as to how the guage works when going past the removed limit, and you get an idea of how big the breasts can usually become with limits.
And you can see in the list of Related videos that the guy's posted many, many more Oppai Slider w/o Limits videos. I don't think they're all there, so you can just click on his name to view the rest. They're all fairly short, so they shouldn't take too long to load. ^___^
Overall, this Breast Size Guage reminds me of an old piece by Woot. ^O^