on my old Sony Xperia Ray with Android 4.0 the bottle neck with crosswalk apps is the devices memory i think, especially for small games there is big difference in memory requirement, could that be the issue of difference between direct play on web and packed with crosswalk?
on this old device the games packed with "normal" cordova Android build run better then when packed with crosswalk although it has to run on poor android 4.0 webview