* Development costs too much to afford iterating.
* Mobile app that customers didn't ask for.
* Language customers didn't understand.
* MVP not actually being viable.
I'm sure there are more, but my take-away is that this was not a lean startup.
If your development costs are such that you can't iterate on new ideas, you might not have a lean startup.
If you are presenting features that your customers aren't asking for, you might not have a lean startup.
If your customers can't understand what you are showing them and you aren't immediately changing it, you might not have a lean startup.
If you are trying to target big and little customers at the same time (or don't know who your customer is), you might not have a lean startup.
If your minimum viable product isn't viable, you...well, you don't have a minimum viable product. The point of the MVP is to provide enough value that customers see more value in using it than it costs. Anything less than that is just some features thrown together.
In the end, I'm not sure if OP agrees with me or not, but this sounds like a focus problem: trying to do to much instead of focusing in on the pain that gets you in the door.
Another note on MVP: It changes over time. Initially, an MVP may just be some powerpoint slides that show your idea. That may be enough to get you some conversations. Later, when targeting your initial customers, it may be a feature or two that helps them solve their immediate needs. Later still, when you want to start mass-marketing, it needs to be something more.
A key takeaway: Just because Lean is simple doesn't mean it is easy. It takes a lot of discipline to keep from putting the cart ahead of the horse.
If your development costs are such that you can't iterate on new ideas, you might not have a lean startup.
If you are presenting features that your customers aren't asking for, you might not have a lean startup.
If your customers can't understand what you are showing them and you aren't immediately changing it, you might not have a lean startup.
If you are trying to target big and little customers at the same time (or don't know who your customer is), you might not have a lean startup.
If your minimum viable product isn't viable, you...well, you don't have a minimum viable product. The point of the MVP is to provide enough value that customers see more value in using it than it costs. Anything less than that is just some features thrown together.
In the end, I'm not sure if OP agrees with me or not, but this sounds like a focus problem: trying to do to much instead of focusing in on the pain that gets you in the door.
Another note on MVP: It changes over time. Initially, an MVP may just be some powerpoint slides that show your idea. That may be enough to get you some conversations. Later, when targeting your initial customers, it may be a feature or two that helps them solve their immediate needs. Later still, when you want to start mass-marketing, it needs to be something more.
A key takeaway: Just because Lean is simple doesn't mean it is easy. It takes a lot of discipline to keep from putting the cart ahead of the horse.