android - Google Play - reduce update size -

i developing game android it´s in open beta , have published few updates already. noticed need download/update whole app, pretty bad bigger games.

my question: can kinda split-up parts of game user needs download smaller parts? (like resource-pack, config-files,...)

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are expension files answer? far understood them, meant big games need more space 50mb , meant used big files.
possible make expansion fack config files, , update ef, making updates smaller?

edit: (see here)

you cannot issue update application changing expansion files alone—you must upload new apk update app.

if understood correctly, can´t update expension file without updating apk, user need download. (and that´s trying avoid)

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manually downloading files
check if there new version of config-files available on server, , if yes, download them before every launch of game. possible solution?

the google play store automatically you; feature called delta updates.

this works on devices running android 4.1 , up, if @ platform numbers, 4.1 , installed on over third of devices accessing store.

i wouldn't spend time on trying implement manually, in future (once more people on 4.1+) pointless.

that said, if find trivial way of implementing means so, wouldn't waste lot of time trying find solution problem solved (for newer devices). people playing games upgrade devices sooner or later.

edit:
think may if fact on devices running 4.0+.
switched 2.3 device (which did not have it) 4.1 device did , assumed (incorrectly) 4.1+ feature. means more 60% of android users have feature :)

also, easy way test if working check progress bar in notification while downloading update large app. reason, notification progress bar shows progress of delta download, while play store progress bar shows full download.