- The max size of a project (aia) in AI2 is 10MB.
- see here (number of files in the assets): Redirecting to Google Groups
- try this server: http://code.appinventor.mit.edu/
- try this approach: How to build a big app → APK max. 100 MB or → AAB 150 MB
The last point will surely work for you too. All my apps are created this way.
Some of my apps contain more than 500 audio files, images, ... in the assets.
See also here: