100 Billion is quite a bit considering I have had an income of 10k with the first two maps and have been waiting for about 3 days and I only have 2 billion?
This is a really easy game and its really fun, the grinding is a little annoying but im doing level 18 missions in the second area as a level 15 and im not having any problems. The achievments are also really easy. I don't see any problems with this game at all.