I got to the end boss: http://www.youtube.com/watch?v=Vn-JevLSaw8

But on my version the graphics glitched (two of my characters disappeared, i had weird camera issues/green background when those characters attacked) i also had issues with moving onto the coloured circles. It made my characters get stuck and disappear on them.

Plus the game actually froze completely during this fight.

Because of those issues, i've had to watch the end of the game on youtube.

I had weird issues with the final battle as well, specifically, one of my characters somehow ended up 500 meters below the battle arena (but still alive and fighting).

I simply restarted the final battle which resolved the issue.

Same for me! I didn't want to restart because of the time it took to get to the final battle (the battle before it).