Thanks for your comment :D
Yeah, I should do with the charset update method, it's a much more better idea than mine.
The design of the original Amiga Apex was so difficult, it seemed impossible to recreate it on 8x8 pixels with proper animation. (At least by me :D )
Thx for the feedback&the bug report, I think I know where the issue is ;) I'll fix it in the next release.
Meanwhile I dropped a message to your FB page ;)