Best way to Feat. Request snappy games not yet maximised?

So I like to play snap.games

& listening to the latest UB-cast, the presenters talked candidly about maximising the potential of some of the software in the store (post Bionic Beaver).

The podcast was was Twelve Years a Slave. (29 minutes long)

For the feedback that was requested - and I think as snaps are ubiquitous with the story, I shall focus on a typical issue with game snaps that I have been experiencing since 16.04

The game OpenTyrian is a game that I use on Solus OS and a snap.

My issue being, that I cannot maximise the window of the OpenTyrian game to fullscreen, or two-screens.

How Do I Change This and correct the issue (as a typical example) ?

I am asking this to guide me and others through this a similar Feature Requests that I encounter with snaps.

https://imgur.com/rBEQ4A1

To go full screen in opentyrian, if it works, you need to press alt+enter while the game is in the foreground. The reason it can’t be “maximized” is because the game doesn’t do any scaling of it’s graphics, and being that the game was originally from the 90s the supported resolution is appropriately for the era 640x480 (VGA).