Very fun little idler.
I had two minor issues, but given thet scope of the game they're not big deals.
1. There isn't really a point to upgrading nests, since it's more efficient to just buy a new one and by the time the space they take up would be an issue you can just afford to delete them. If you plan on expanding this or anything I'd reccomend having nests be unlimited and make upgrading them be more expensive but let you buy higher level creatures for a higher price.
2. I'm not sure what upgrading ATMs does, if anything at all.
Those aside, great little game