Family 2 — "fill the screen with your own art." The background layers are the SNES's canvas. This family is a ladder through the PPU's background modes, from a single Mode 1 image up to 256-colour and hi-res, each mode a different trade of colours against layers against resolution.

The ladder

Rung	Example	Developer question
2.1	mode1	How do I show a background from a PNG (the canonical Mode 1)?
2.3	mode1_lz77	How do I load a background from compressed data?
2.4	mode1_bg3_priority	How do I make BG3 draw in front for a HUD overlay?
2.5	mode0	How do I run four 2bpp layers (Mode 0)?
2.6	mode3	How do I show a 256-colour (8bpp, Mode 3) background?
2.7	mode5 · mode5_hires	How do I use a hi-res (512-wide, Mode 5 + interlace) background?
2.8	mode2	How do I scroll each column independently (offset-per-tile, modes 2/4/6)?

Under-the-hood rung to come — 2.2 a tilemap built by hand in C: what the asset macro hides, for the fundamentals/ tier.

Moving the world past the camera lives in its own family: scrolling/.

The idea in one screen

A background is tiles (8×8 pixel art in VRAM) placed by a tilemap (a grid of tile indices) and coloured by a palette. A mode picks how many layers you get and how many colours each: Mode 1 gives two 4bpp layers + one 2bpp (the workhorse); Mode 0 gives four 2bpp layers; Mode 3 spends everything on one 8bpp (256-colour) layer; Mode 5 trades colour for 512-pixel width. Same three ingredients, six trade-offs — pick the mode your scene needs.

Mode 0 — 4-Layer 2bpp Background Mode 1 Example Mode 1 BG3 High Priority -- HUD Layer Over Backgrounds Mode 1 LZ77 mode2 — offset-per-tile: per-column scroll from BG3 Mode 3 — 256-Color Background Mode 5 — Hi-Res 512×256 Background Hi-res text — BG Mode 5 + interlace (512 × 448)