The game is simple enough to pick up and looks good. One thing that was not clear from the start was that you can click on the triangle to change the direction it will move.
I also got stuck on level 4 (funnily the gif of your game shows this puzzle). Would have loved to try out other puzzles so I would not recommend unlocking puzzles only if you beat the previous one, especially in a jam.
With some polish and explanation, maybe a hint system and more puzzles this could work well as a casual mobile puzzle game.
Great job !