Parallax platformer questions

I’m not in tiles, im creating all my environment artwork in 3x 1920 wide and successfully have it working as a Parallax scroll on repeat.
If I’m creating the actual floor/ level for the character to walk across with ups and downs, different gaps jumps etc, that’s say needs to be the length of maybe 20x widths of 1920 for a decent little level size, do I just paint the whole 20x 1920 artwork as a single layer in Ps then obvs add colliders etc ?

For platforms look up at how to make sprite sheets and 9-slices. You can do what you said and paint the whole level platforms but depending on your game you would generate huge files, creating tileable sprite sheets and 9-slices will save you on that aspect and make level creation easier.

Thanks, helpful, but how does a game like Ori and the blind forest achieve or Gris achieve this? their levels are lengthy but there are no repeating sprites as such unless they’re the odd interactive asset , thanks so much

It may seem that everything is is unique but with clever placement you can make it look like that. Some things do repeat. Maybe something doesnt repeat in a specific area but later on it may do it.

Anyway, you can still paint whole stages as long as the file sizes won’t be a detriment to your game and everything is accounted for.