We have a list of fullscreen options:
-Scale (keep proportional and show outside of layout, is going to add some empty space on the right if the window is too large or at the bottom if the window is too high. It probably needs a new resonable name, maybe Proportional Scale or Scale with Ratio)
-Letterbox Scale Integer
-Stretch (New) according this thread
In that case, the assets and level logics have been set with a 800x480 resolution in mind. If we like to fill a complete 1080p screen or a 1366x768 tablet... I need to build higher resolution assets to match these resolutions it would waste the time.
Otherwise, I can use a scaling operation which can cover the screen to enjoy the gaming experience.
The game is still playable.
Most of the modern console games are not developed in 720p or 1080p. Almost all of them render the game in lower resolutions like 1024 x 768 and let the GPU doing the process. It helps boosting the FPS and save memory in most cases.