That's awesome to hear! We do apologize for the main menu; for this first build we definitely spent more focus on getting the core gameplay mechanics setup. 9 minutes sounds about right what we hope to aim for with a myriad of procedural levels with more bosses and enemies!
We promise the next build to come will have more enemy types, more bosses, more room types, more levels to show off the intended progression, and of course, a more impressive main menu!
Thanks again and we appreciate the feedback!