Hello! I was one of the streamers who took part in Feedback Quest, and I'm here to leave some comments I had while playing.

Or I would, but it seems many people have spoken about it. I do hope that you will be able to do more work into this and polish it. I would recommend maybe combining mouse and keyboard, where you click on a can you want to move and then use the keyboard arrows to move it around. Currently, doing it with clicking is slow and repetitive.

That said, I have no idea why some cans change instead of instantly disappearing.

As others have stated, there's no animation for matching cans together, it seems like an asset that's not being used. I liked the game but it seems to be missing a lot, like perhaps a score for matching more at once, or some kind of feedback of how you're doing in the game. The UI of course needs work, especially the level transitions. When I won the game, the game just closed immediately, the congratulations screen showed for about half a second. 

I really like puzzle games and this made me wanna play more columns, keep it up :)

I played through the 4 levels, the animation and music is nice, though sometimes the clearing animation doesn't trigger when you line up the cans. Also it would be nice to be able to line up 4 cans or more.

One problem at the moment is that there is no raise in difficulty between the levels. In fact there is no difficulty at all because you can move the cans around as much as you can, so it's impossible to lose. Those metal cans seem like they should be obstacles somehow (unmovable or indestructible) but they disappear on their own after a while.

This is a good basis for a match-3 puzzle game, what you could add next is the ability to make combos (cans could fall when there is no can underneath anymore and any new combination of 3 or more would trigger and so on on until there is no more match to trigger), and you could add losing conditions, maybe by preventing the player to "switch a can with nothing". There could be an infinite mode where the goal is just to score the most matches before no more matches are possible 🤔 

You could add cans with powers too, like a can which makes all cans of a color disappear when it is matched with two cans of that color.

There are a lot of possibilities from where your game is right now, cool work!