The game kept skipping the tutorial for some reason so i couldn't figure out how to reload. After a couple restarts and unplugging my controller, it eventually loaded and I had a good bit of fun playing your game until it crashed (others have covered that so I will say no more.)
No soundtrack is better than an annoying soundtrack but sound effects always add some impact to what you're doing. They are also good feedback when animations are not clear. (Your game has great animation but a sound effect for each action always helps the player know their input is impacting the game). As for time constraints, my game's sound effects took about half an hour (7 clips total). Most are just 3 1/16th notes played in LMMS. That's just my opinion of course, but it really does not take long compared to how much it could add to your next game.
You really seem to have known what you wanted to build and it has the polish to show it. The expression on the crate's face is the main reason I clicked on this... just so you know.