Good analysis. It sounds in principle that for OP there isn't really much options to win big, sometimes that happens in startup land - mentally it is good idea

Good analysis. It sounds in principle that for OP there isn't really much options to win big, sometimes that happens in startup land - mentally it is good idea to admit that this project wasn't personally very successful and start thinking about next moves. Most important here, I think, is to act in polite and professional manner. It is not uncommon in these situations for everyone to lose because things get personal. Just try to find some kind of deal where you are likely to get some value.