Large Tilemaps

I have a large game that uses large sprites. The code is minimal because the game will be submitted for the student Adobe competition in the game category in a few weeks and they want to focus on the art side of things. I wan't to showcase the art which is being made in photoshop so the levels and sprites are large (the main sprite is 128x128 and the level is 11520x6580). Should I use several Large tilemaps on 2-3 layers that are large (1024x1024, each tile is 256x256 in size) or should I just draw a few large sprites that fit together to create the "floating islands" in my game?

any help would be apprecitated

You should probably use the lowest resolution tiles on a tilemap that still looks acceptable to you. Without seeing how your tiles are configured, it would be difficult to advise much beyond that.