As a professional web dev, I appreciate anyone able to make a game using vanilla JS (on a phone nonetheless, you are a madman!!) If you are trying to learn web dev, great job!
Now for the game itself, unfortunately I had no idea what was going on, or what the goal of the game was. The game seems completely bugged as well, since the black cube doesnt really go where you click. (I have realized this happens when you click directly on the balloon.)
Now if you are limited to developing on your phone, dont lose hope! I recommend you check out Godot for android, or if you want to continue with JS, you could give Phaser a try! https://phaser.io/
Music is a jammer though, I must say.
If you want to fix the movement, use `event.x` & `event.y` here instead, seems to work for me:
The other problem is that your collision detection seems to be running way too slowly at 700ms. The proper way to do it is have a signal for collisions instead, but that is way out of scope for using vanilla JS like this (the actual bottleneck here is reading the position and size from the dom, not the collision check itself).