Cool ... thanks for the info.
I've decided on a few changes:
1 - Going to get rid of the micro transactions so no more extra gun and extra health purchases. Instead, everyone will get these for free. I've also added an extra gun for each girl.
2 - Remove the boosts as in-app purchases. Instead, everyone gets more boosts to begin with and you can get some more by just leaving a review for the game.
3 - Only have one in-app purchase and that is to remove ads and unlock levels 8 to 28. As part of that, you also get some extra boosts to use.
Anyone that's already made an in-app purchase won't be affected and won't notice any changes. The levels will remain unlocked for them. Essentially the same as a trial option but using the in-app purchase tools. I'll explain that the game has only the first 7 levels free in the description.
Otherwise, update is almost good to go. I heard back from my playtester that it runs smoothly on a 520 even with the new graphics. I've replaced the pistols for both girls with interesting sub-machine guns. I've also added infinite ammo for those starter guns. Going to make a few more tweaks and then hit the submit button. Hopefully some time today .... if not, definitely tomorrow.