It looks great and is fun! Couple of UX suggestions:
On my window configuration (1 window in each corner, 4 total, on a 4k monitor), controls were below the view port and no scroll. Possible resolutions.
Allow vertical scroll, seems like this would be required for mobile anyway
Move controls to side if space available
Change layout to use less space
When it loads the next puzzle, there should be a transition. Some noticeable change on the puzzle area. Could be an quick animation or just resetting the highlighted row/col back to default. It took me a second to realize the puzzle was different after I hit next puzzle.
Touch/mouse controls. Example: when the mouse hovers over a piece, that should be the highlighted row/col. When they drag, that should be the direction the row or col moves. I'm sure I would get used to the keyboard controls if I played a lot, but they were awkward for me. Even up to the finish I was mistakenly shifting a row/col before I selected it. Even as a keyboard/mouse gamer. Once you get mouse controls working, there won't be a need to display the row/col highlights unless someone starts using the kb controls.
Make the timer optional. For me puzzles are relaxing. Nothing kills that like a timer. When the timer is off, use alternate scoring goals like minimum number of moves. It's probably a good idea to do multiple goals anyway to cover different kinds of players.
In all this is a great game with a lot of potential. I can imagine larger grids, wild card colors, fixed pieces that can't be moved. And other kinds of mechanics to keep the puzzles interesting. I'd probably spend too much time playing it.
It looks great and is fun! Couple of UX suggestions:
On my window configuration (1 window in each corner, 4 total, on a 4k monitor), controls were below the view port and no scroll. Possible resolutions.
When it loads the next puzzle, there should be a transition. Some noticeable change on the puzzle area. Could be an quick animation or just resetting the highlighted row/col back to default. It took me a second to realize the puzzle was different after I hit next puzzle.
Touch/mouse controls. Example: when the mouse hovers over a piece, that should be the highlighted row/col. When they drag, that should be the direction the row or col moves. I'm sure I would get used to the keyboard controls if I played a lot, but they were awkward for me. Even up to the finish I was mistakenly shifting a row/col before I selected it. Even as a keyboard/mouse gamer. Once you get mouse controls working, there won't be a need to display the row/col highlights unless someone starts using the kb controls.
Make the timer optional. For me puzzles are relaxing. Nothing kills that like a timer. When the timer is off, use alternate scoring goals like minimum number of moves. It's probably a good idea to do multiple goals anyway to cover different kinds of players.
In all this is a great game with a lot of potential. I can imagine larger grids, wild card colors, fixed pieces that can't be moved. And other kinds of mechanics to keep the puzzles interesting. I'd probably spend too much time playing it.
I have made fixes that should address most of the issues you listed. Thank you for the feedback.
Regarding timer optional, I will look into it.