Some bugs you should consider getting rid of...
The most frequent one I've had with the demo is the Support character freeze bug. When in battle you can summon your support character to the field to help you out, instead nothing happens and the game freezes, the only thing that can get around this is just refreshing the page and continuing from the last save game.
Another bug is related with the shop where you cant buy an item even though you have enough money for it.
Thirdly there was a weird bug where I made Axl use a Energy Capsule SX or something like that on a low HP Zero, now one of the enemies attacked Zero and knocked him out but instead of Axl using the healing item on a living team-member he used the healing capsule on Zero returning him from the dead but leaving Zero with the K.O Animation.
Other then that I haven't found too many bugs at all. It would be nice if you could change the character you play with outside of combat to for example Zero or Axl instead of always having to run around as X.
And another thing; Please for gods sake don't tell me you are planning on making Sigma a playable character in Chapter 2, he is a villain to the bone and deserves to stay as such, I would much rather have Sigma replaced with Vile as he is more fitting with X-Zero-Axl & Dynamo plus that guy is awesome x3.
All in all I'm waiting for your next installment for the game and I hope you can finish it soon so I can get to play it! :D