Ok so like you stated this is a prototype so it is incomplete... However,
What is here is really good, the sprites look amazing and they really nail the Megaman X look ^^
The animations and camerawork are also great, i like the subtle squash and stretch there is on some actions, and how the camera zooms and unzooms depending on movement.
The main character art on the title screen is also absolutely awesome, i dig her design !
The music on the tite screen was also really good with that classic genesis sound.
From what is here, you've got some nice elements already, so no doubt with more time you'll make a cool game from this.
Well done to you guys and your comissioned musician :)