Can I change button label so it can serve two functions?

I need to design a game start screen, where there's a PLAY button waiting for the installation to complete. But the user has a possibility of stopping the installation which would result in a new screen appearing, where they can start the installation manually from the start.

My question is if I can change the label of this PLAY button to INSTALL on the last screen, mainly to save some space or not to have to leave blank space for the other button to show up later (or never, if the user never stops the installation).

Same I guess would be applied to an update screen and other that need some kind of loading that can be stopped and started manually again.

Thanks!