That's quite nice game, i liked how big Nessa's belly grew, these growth sounds were amazing. But there's few problems with it. 

It took me 22 recharges to reach her maximal size, because the gem has limit for maximum charge. Why not remove this limit? This would help reaching max size easier.

Also, after reaching max size, you can't revert the growth, so Nessa just stays with gigantic belly. It would be nice to have size control buttons after reaching max size, to revert belly size back to normal, or grow it large again.