Do Image sizes matter?

NOOB ALERT. Long time supporter, but still learning the basics.

I've imported some images for my game, however they are HUGE. So i've resized them in C2.

When I submit the game would the size change be incorporated or will C2 games run as the original size and use the Ram/storage of the bigger image instead of the resized one?

Do I need to resize it in photoshop then put it back into C2?

I plan on having this game very high on animations.

Also - I set a tiled background and the Tiles are huge as well. Is there a way to resize the Tiled background so it's not so close up?

Thanks in advance, hope you're all having a lovely day. ^_^

Construct makes a copy of the source image. If you change the image size in the C2 editor, thats the size of the image file, and tyhe size it will be on export.

So it uses the resized version? perfect! Thanks.