I think it depends on how you explain it, because it's bound to be asked about. If you can spin it as a learning experience and perhaps assuage worries about you jumping ship to start another company, any human recruiter (and most are) would interpret it as a plus.

On the other hand, if all you talk about are mistakes and failures to learn from them, or suggest that you'll be leaving at some point to do it again, a recruiter is likely to worry.