How do I create a Brave New Sandbox

I'm aiming to create a one big sandbox level. And I'd like it to be mobile friendly, too.

Any ideas, tutorials... opinions on feasibility?

I'd been told of this method, of loading the level thru an array. I found some tutos, but they're too cryptic for my nooby brain. Can anybody explain me the basics (very basics) of this? Is it what I'm looking for?

*By big i mean 25600x14400, with a screen window of 480x270. Here's a sample of what i'm trying to do. Its a very rough demo, will be destroyed in a few days. Still is mostly empty and undone, and already performance on phones is giving me the pains.

Bump! Nobody wants to make a sandbox? C'mon people where's your megalomania??

As this array thing looks rather too difficult for me apelike coding prowess, I'm currently struggling with other idea: i'm replacing (or intend to) dormant offscreen sprites with tiles from a tilemap, which should be lighter. Then is always possible that after all the effort it proves useless, performance-wise.

Take a look here, there might be something of use.

https://c2tutorials.wordpress.com/tag/array/[/code:1j2e9hb0]

Your game demo looks very good.