5 years ago I co-founded a startup with 3 of my friends. At the end of the 5 years, we ended up burning nearly 700 $ K and never got the product to market.
Here are some visuals of the product I designed. (I'm a product designer)
One of the main problem people were reporting us was the wire so I worked on creative ideas to take advantage of it instead.
Woah. $700k is an expensive endeavor. Did you try to sell/license your design to anyone else? Collecting royalties would hopefully allow you to recoup some of your costs.
I launched a fairly basic product last year and am still working on the marketing. I've received great reviews from the people I get it in front of and have sold to, but its a matter of finding a way to get mass adoption.