But onto the issue at hand: there seems to be a bug related to adding notes with the pen tool. Clicking in certain parts of the grid places notes into wrong cells - see image:

It seems the note placement hitboxes (shown here in red) are offset to the left by half a width of a cell. This makes placing notes with the mouse quite difficult.
I'll keep an eye out for other bugs.
Keep up the good work, muzycian!
