All things considered, I've had a fair amount of issues with the crosswalk wrapper. Back button binding doesn't work, CPU utilization jumps (not a game logic issue, even a 10 event game burns battery), home button hard crashes the app, window button works, but when you go back to the app it can sometimes hang, and other times the sound cuts out. There are also issues with script minification (though, there issues with that in regular HTML5 export as well) and gamepad support doesn't work (using r161) on Android. At least, I haven't been able to get it to work with an Xbox360, or a PS3 controller hooked up to my N10. Obviously a limited testing environment, but still...
I think I might hold off on deploying to the Play Store until the wrapper is a bit more stable. Don't want 1-stars because the wrapper keeps crashing :(
Oh, also, exported app (pre-crosswalk) 18mb. Installed app on phone, 58mb - what?
I think you might want to reinstall Construct/Intel XDK, you have some serious problems there.
I have tested my game on 7 different Android devices so far and the results are the same:
Back button binding works perfectly for me: (Broswer > On mobile back button pressed). Can't comment on CPU utilization but I've not noticed any abnormal battery drain. Home button works as expected for me. By "Window Button" do you mean the Recently Used Apps list? I haven't noticed any issues myself. Can't really comment on anything else as I have not yet implemented sound into my game but I know this is a known issue and I haven't attempted the use of a gamepad.
The export app size is indeed a rather serious problem that needs to be addressed. Mine is also installing as ~52mb (although the 18.2mb that mine exports as is still FAR too big as Cocoon's export is only 8.5mb).