Thank you for your kind words and feedback!
We found at first "Restart" was pressed too often due to forgetting the undo button exists, hence the hint, but we agree this shouldn't pop up every time you want to restart. Not to mention you are correct that undo is so powerful it can undo a restart, which we will definitely look at fixing post jam.
In the regards to the "redo" button, what would you like to see that do compared to an undo or restart button?
Also, well done for reaching the boss!
A redo works the same way redo works in most non-game software (e.g., text editors and drawing programs), or like how the "forward" navigation button works in a web browser. Undo moves backwards in history, and redo moves forward in history. The player performing an undoable action causes that action to be inserted at the current point in history and all future history to be erased. It's really useful for times when I accidentally undo too many times and want to quickly get back to a future state without having to manually perform the same actions again.
Patrick's Parabox is a good example of a sokoban game with a redo button.
