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diff --git a/space/src/space.s b/space/src/space.s
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+;;;
+;;; TODO: reduce the scope of this to just:
+;;;   - Movement through subpixels.
+;;;   - Shooting (no collision or anything)
+;;; -> link to jetpac.nes for more stuff
+;;;
+;; This is similar to the sprite.s example, but it expands on it greatly into a
+;; full game by:
+;;   - Having a moving background.
+;;   - The ship can be moved:
+;;     - The movement is done through subpixels for a smoother experience.
+;;     - The ship's sprites are updated accordingly: resting, acceleration, full
+;;       speed.
+;;   - Random asteroids will appear from time to time and they can collide with
+;;     the ship:
+;;     - A collision decreases the live status from the ship (cracks will appear
+;;       to the sprite).
+;;     - When the live status reaches 0 -> game over.
+;;   - The ship can shoot and destroy asteroids.
+;;   - There is a score.
+;;;
+
+.segment "HEADER"
+    .byte 'N', 'E', 'S', $1A
+
+    ;; 2x PRG-ROM; 1x CHR-ROM
+    .byte $02
+    .byte $01
+
+    ;; Horizontal mirroring, no special mapper.
+    .byte $00
+    .byte $00
+
+.segment "VECTORS"
+    .addr nmi, reset, irq
+
+.segment "CHARS"
+    .incbin "../assets/space.chr"
+
+.segment "STARTUP"
+
+.segment "CODE"
+
+.include "../include/apu.s"
+.include "../include/oam.s"
+.include "../include/ppu.s"
+.include "../include/joypad.s"
+
+.include "states/game.s"
+.include "states/player.s"
+.include "vectors/reset.s"
+.include "vectors/nmi.s"
+.include "vectors/irq.s"
+
+;;;
+;; This is our main subroutine, the reset procedure will call at the very end of
+;; initializing the hardware.
+;;;
+.proc main
+    ;; Before starting the game loop proper we initialize all our assets: load
+    ;; the palettes, nametables and sprites for this game.
+    jsr init_palettes
+    jsr init_nametable
+    jsr Player::init
+
+    ;; Reset scroll.
+    bit PPU::STATUS
+    lda #$00
+    sta PPU::SCROLL
+    sta PPU::SCROLL
+
+    cli
+
+    ;; 7: allow NMI; 5: sprite size is 8x16; 4: background pattern table starts
+    ;; at $1000.
+    lda #%10110000
+    sta PPU::CONTROL
+
+    ;; 4: show sprites; 3: show background; 2: show sprites in leftmost pixels
+    ;; on the screen; 1: same as 2 but for background.
+    lda #%00011110
+    sta PPU::MASK
+
+@main_game_loop:
+    jsr Joypad::read
+    jsr Player::Movement::update
+    jsr Player::Sprite::update
+
+    ;; This is a hand-shake between the code on `main` and the code on the
+    ;; `nmi`. See Game::flags for more.
+    SET_RENDER_FLAG
+@wait_for_render:
+    bit Game::flags
+    bmi @wait_for_render
+
+    ;; Rendering is done, we can perform another iteration of the loop!
+    jmp @main_game_loop
+.endproc
+
+;; init_palettes copies all the palettes for our game into the proper PPU
+;; address.
+.proc init_palettes
+    PPU_ADDR $3F00
+
+    ldx #0
+@load_palettes_loop:
+    lda palettes, x
+    sta PPU::DATA
+    inx
+    cpx #$20
+    bne @load_palettes_loop
+    rts
+palettes:
+    ;; Background
+    .byte $0F, $12, $22, $32
+    .byte $0F, $00, $28, $30
+    .byte $0F, $28, $16, $2D
+    .byte $0F, $28, $16, $2D
+
+    ;; Foreground
+    .byte $0F, $00, $05, $30
+    .byte $0F, $00, $00, $00
+    .byte $0F, $00, $00, $00
+    .byte $0F, $00, $00, $00
+.endproc
+
+;; init_nametable loads the relevant data to the nametable that is then going to
+;; be used in order to build up the background.
+.proc init_nametable
+    bit PPU::STATUS
+
+    ;; Big stars.
+    WRITE_PPU_DATA $20C8, $02
+    WRITE_PPU_DATA $227A, $02
+
+    ;; Small stars.
+    WRITE_PPU_DATA $20B9, $04
+    WRITE_PPU_DATA $21CE, $04
+    WRITE_PPU_DATA $21BA, $04
+    WRITE_PPU_DATA $22B8, $04
+    WRITE_PPU_DATA $22E7, $04
+
+    ;; Select palette 1 for one of the small stars, giving it a red-ish look.
+    WRITE_PPU_DATA $23CE, %00000001
+
+    rts
+.endproc