Don't ever use Crosswalk. It is only compatible with around 100 devices. Always build directly as Android in the Intel XDK program,
My game went from 40 MB down to 4 MB.
Crosswalk is compatible with WAY more than 100 devices. With the normal Android export you get way worse performance and lack many features that Crosswalk supports.
That is, UNLESS you intent to only target Android versions with Lollipop or higher. Those have Crosswalk technology built in.