Delete internal storage download for a (system) game app I downloaded?

[frozenbase]

So, GameLoft's Let's Play Golf 3 teaser app was on my new phone. We'll, I stupidly opened it, and it required a large download of like 400MB, which is now eating up 40% of my phone's internal memory. The game is just two levels, before you must upgrade/buy. I don't want it. I know you cannot get rid of it as it was a system app, though I know how to disable and thus hide it using the settings. But how can I revert it to its original state of a mere hundred kilobytes? That is, how can I remove the downloaded part that was 400MB?

I'm hoping there's an easier way than a system reset.

Thanks!