OnTriggerEnter2D not working

As Johan points out above, if you post a code snippet, ALWAYS USE CODE TAGS:

How to use code tags: Using code tags properly

Go check the docs for the OnTrigger function and make sure you are meeting all of the requirements to receive that callback. With Unity the answer is never just code; it has to be integrated correctly too.

And also as Johan suggested, use Debug.Log… a LOT. To help gain more insight into your problem, I recommend liberally sprinkling Debug.Log() statements through your code to display information in realtime.

Doing this should help you answer these types of questions:

  • is this code even running? which parts are running? how often does it run? what order does it run in?
  • what are the values of the variables involved? Are they initialized? Are the values reasonable?

Knowing this information will help you reason about the behavior you are seeing.

You can also put in Debug.Break() to pause the Editor when certain interesting pieces of code run, and then study the scene

You could also just display various important quantities in UI Text elements to watch them change as you play the game.

If you are running a mobile device you can also view the console output. Google for how on your particular mobile target.

Here’s an example of putting in a laser-focused Debug.Log() and how that can save you a TON of time wallowing around speculating what might be going wrong: