It's cool that strategies matters. I really enjoy the game when I'm thinking how to arrange my team. But there's clearly some bugs that shows a lack of play tests. You can drag your party member out of the team to kick them out. If I only have one member, the game breaks. If only healer survived, the game cannot end because enemies cannot kill the healer. Maybe adding a limit of rounds will be nice.
The UI is a little confusing. It does not show exactly how much hp every character has. All they have is a bar in the same length. I cannot really tell which has more hp. This makes my strategies meaningless in some situations. Also, the UI does not really fit the theme of an MMORPG world.
I love the arts, especially all of them have a tiny pointy head.
As for the music, it is good by itself. However, it has the same problem as the UI. It does not fit the theme of an MMORPG fantasy world. It is too cute for it. I would expect a fantasy-ish, middle age tavern style music, like the Hearthstone but more battle-ish.
By the way, one of the username is 1ll1lll111ll , which makes no sense. I don't know if you wanna try to make fun of it or something else(it's not funny anyway). Check my name, it's upper case 'i' and lower case 'L'.
All in all, the system, arts are super great, but you do need to spend more time on making all the functions work well together, and fitting all the stuffs into the theme. I can tell you tried hard on making all the parts, but they just feel not good together.