My recommendation:
Go to the lowest resolution you can find that “feels” good. 1280x720 can work, but note that if someone is on a 1080p monitor and makes the game fullscreen, it will look distorted (because 1080p is 1.5x 720p, and therefore every one pixel is turned into 1.5 pixels, so not scaled evently).
If 640x360 can work for you, that’ll be MUCH better as it can evenly scale into 1280x720 AND 1920x1080. (and 1440p too).
If you didn’t need the high resolution assets, I’d recommend you started even smaller, like 320x180, so you’re working with the native asset size.
All of this said, even if you’re using those lower resolutions, what you should do is at the start of the game; change your resolution higher, then zoom in your camera an inverse amount.
e.g.:
- Your game is designed for 640x360.
- At the start of the game, you use the event to change the game resolution (and NOT scale your assets) to 1920x1080. This is 3x the size of your game assets design resolution.
- In the same event, you then zoom all of your layers to 3x. This will have your assets appear at the same size as if your game resolution was 640x360.
Why do this? This allows you to have a higher internal resolution (What the scene is actually rendered at) vs your assets, which means you have more position/pixels to work with. This is greatly beneficial because it will allow the following:
- Smoother camera movement
- Smoother object rotation
- More positions for smoother tweened animations.