Current update method for Playstore requires a 1.5 Gb download from the APK and a subsequent 3Gb or more download after installing new apk.
This usually takes quite a long time and leaves the phone unusable until it's done, slower download speeds making this wait-time even longer.
Please consider allowing for the in-game download to be run in the background (secondary update service) similar to how Play Store handles APK updates.
As reference, APK updates from Playstore allow the download to run in the background as a service and allow the user to still interact with the phone's other applications.