These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Game-Breaking Bug: The Assist Tick bug, which will crash Stempania if you have the assist tick on in the editor and you stop testing a chart. Happens randomly too, and only in the mode people would use the assist tick.
Ironically, the only reason it was patched out was because it messes with scoring. The update immediately after the above adds a much easier to use variant that also plays nice with the scoring system.