@qedrakmar 1,48e71 is scientific notation, and 148e69 is enginneering notation, the magnitude increases by 3, so it's e3 - kilo, e6 - mega, e9 - giga, etc. I'm sure you know that, but this is not a mistake ;) cheers :)
About "locking the buy buttons if you can’t afford the full 10" - make it toggleable :) I thought earlier that locking them would be totally unnecessary and would lower income, but now I have so much money, that I prefer to have nice round numbers than to have a bit more income ;)
So for early game it would be nice not to have them locked, but after certain point it is visually appealing.
BTW, great job developers! I second Sarah's opinion - while the game is truly one of the best idle games, you are second to none! I wish any big companies had your approach to gamers...
Like the previous one, this was also entertaining :) However, I would like to see some more cities or difficulties, because you don't really need to buy that much upgrades as possible to invade whole world, and even Newgame+ is not so much a challenge. More cities' achevements/challenges would also be nice. And probably new stat to upgrade: field/distance of view of zombies; sometimes it's really annoying to see one survivor left just because all your zombies are on another side of screen. But that is probably an idea for next sequel :) Overall: Very good game, very good sequel, and there are fields to upgrade it yet more :) 4,5/5 - rounding 5/5 and favourite.