Here is how a level selector screen looks like in the game. You can scroll a line of levels and load a hovered level
I don't like when a game doesn't show you what the level is about on a selector screen. And I've solved this by showing to player how a map of a level looks like. I will probably simplify these maps a bit and only show floor, walls, player, exit and enemies. Will see.
This line doesn't show you levels that you haven't passed yet.
Each level "card" is just a bunch of meshes and a canvas with a text. This all is generated when a player launches the game. Animations are made using spring implementation which is described here (i love it so much and i'm afraid to overuse it :D)
And yes. I save levels as a 16x16 pictures where each color means a specific object with a rotation. This is just hardcoded in a level generation class. Kinda works.