Great version, I really like the convenience features (filling multiple slots to right/down, the position indicator, etc.). However, I missed being able to multi-fill X's. Also, I found that pressing left shift while pulling down the joystick enables me to X squares in the column, but I could not find the key to do that horizontally.
Well, I also want the game to work with the c64 mini, so controls need to work with just joystick, and my solution for that is double clicking fire to set X on empty, or ? on filled, keep fire down and move stick to set multiple. For consistence I'll also try to support holding X or V while moving the cursor to set multiple. Turns out left shift + fire is a ghost key, so if any other kb solution causes ghost keys causing other effects I won't be able to...