Breaking the grid

The weakness of tiles is obvious repetition — a floor of one identical tile reads as a checkerboard. The fix is variation: draw 2–3 alternate versions of a common tile (a crack here, a pebble there) and sprinkle them in. The eye stops noticing the grid when the surface has occasional differences.

• Make a few variant tiles for any large repeated surface
• Add decorative "decals" — flowers, cracks, stains — placed sparsely on top
• Do not overdo it: too much variation is as noisy as none is boring

Assembling a level

Build a level in layers: a ground layer, a walls/collision layer, and a decoration layer on top. Keep the tileset consistent (one palette, one light direction) so the whole level reads as one place, then export it for your engine.