How to add new levels without increasing the game apk size ?

Hey, I just realized, some multi level games (50-100 level) are 15-20 MB. How is that could be possible ?
The game that I made has only 10 levels and the size is 57 MB even I compressed the images and imported as 256 or 512 px. How can I keep the size minimum in my 2D game ?

For example this game has 80 levels and 19 MB:https://play.google.com/store/apps/details?id=com.cooyostudio.penguin.run

Hello,

You don’t need to think about it as adding new levels just like the others without increasing the apk size, think about optimizing the current ones, and add some new ones based on the same optimization model.

First of all, read about Asset Bundles, you’ll save a lot of hassle with those. I recommend a detailed read through this article: Assets, Resources and AssetBundles - Unity Learn. It will really wrap your head around Unity objects and assets and resources.

Load sprites/animations/whatever from Resources only when you can’t assign it in the inspector. When you import images and textures and whatever, shrink them down until just before they start looking bad.

How do you make your levels? Do you build them in the scene and then save each one as a prefab? Or do you build it dynamically? Are they tile-based? There are a lot of options. What i can generally tell is that, in my opinion, the first option is bad.

Secondly, the size may not only come from your images. Do you have audio in your game? Compress it. Every piece of audio. Just compress it. And my last tip is be careful what you put in the Resources folder. Absolutely everything in there gets included in your apk and will increase the build size.