"ERROR: remove_from_group: Condition ' !data.grouped.has(p_identifier) ' is true. At: scene/main/node.cpp:1828" kept popping up in the console window. Also stage 9 didn't register the solution the first time I solved it. Other than that it worked much better than most jam games I've seen, including feeling more finished. The one thing I can think of that would've made it better is a rewind button so that accidentally pushing too many times wouldn't result in having to redo the whole puzzle.