yes I remember this example! I can only give you a high level comment, which I suggest taking a look at the guideline
What I noticed in you code is that you changed basically two major things - you are using tensorflow.js which doesn’t seem to be included in Dan’s example (or does he have another example that uses tf?), and you changed the “game” itself from the flappy bird to balloon popping. So, first it’s important to separate them to see which is actually causing the issue (the neural net or the game logic, or it can be both of them)