I tried the amkp solution, I built the app for Android without crosswalk and installed it on my Xperia Z2 with Lollipop. The results are greatly insane:
With Crosswalk:
Apk about 18 Mb and installed <60 Mb
Without Crosswalk:
Apk 417 Kb and installed 1,57 Mb
The only flaw is the performance that worsen, too much for my physical game.
This is really a big problem, I hope that someone in the future work on this, I'm undecided whether to continue the development of the game or not, I do not know if it is worth it..