A good attempt at making a hyper-casual single control game. Decent visuals and responsive controls contribute to a nice little experience.
I think one of the key problems is that the controls are like having a lead foot whilst driving. Pressing the key longer than half a second causes the block to fly offscreen, so some tweaking to how the blocks movement would go a long way to making the player experience better. Secondly, there is no consequence to flying off the top of the screen and the fail condition just makes the block stop and you have to hard reset the game. An end condition would really help this game out as well as an upper boundary. Consider how you export the game, is there a better way you could have done so?
All in all, a good little game that just needs some tweaking to the user experience and end conditions to be a great first submission.