Simsu is a basic Sudoku game. You can switch between filling in
notes (pencil mode), or filling in answers (pen mode). To make it
easier to see where to place numbers, you can highlight all
instances of a number. You can also check your answers for
correctness while playing. The game stores your current notes and
answers, so that you can pick up where you left off the next time
you play.

NOTE: Versions newer than 1.4.0 require qt6. I will probably wait
to update it once it is in stock Slackware, because that's a huge
dependency for a relatively simple game.
