Here's a demo that shows procedural generation using SpriteTile. A 1000 x 1000 level (for a total of a million tiles) is generated at runtime. Note that the entire level only uses 11MB, so you can have extremely large levels without needing complex paging techniques. Also note that this demo doesn't use physics or “real” colliders; instead each tile is simply marked as “collider” or “not collider” as appropriate, which is perfect for square-by-square movement and uses hardly any resources. Of course physics colliders are also possible if desired.
Click in the window below to start. You can move around with the arrow keys, and hold shift to move faster. You can generate a different level by entering a new number and clicking the “change level” button. Clicking on a tile toggles it from floor to wall and vice versa. This demo and others are included when you buy SpriteTile.