diff --git a/builtins.ts b/builtins.ts
index c9e709c..1259105 100644
--- a/builtins.ts
+++ b/builtins.ts
@@ -8,42 +8,13 @@ import { font } from "./font.ts";
 import { addToContext } from "./runcode.ts";
 import { resetRepl } from "./repl.ts";
 import { COLOR } from "./colors.ts";
-
-// deno-fmt-ignore
-const sprites = [
-	[
-		2, 2, 2, 2, 2, 2, 2, 2,
-		2, 1, 1, 1, 1, 1, 1, 2,
-		2, 1, 1, 1, 1, 1, 1, 2,
-		2, 1, 1, 1, 1, 1, 1, 2,
-		2, 1, 1, 1, 1, 1, 1, 2,
-		2, 1, 1, 1, 1, 1, 1, 2,
-		2, 1, 1, 1, 1, 1, 1, 2,
-		2, 2, 2, 2, 2, 2, 2, 2,
-	],
-	[
-		2, 2, 2, 2, 2, 2, 2, 2,
-		2, 3, 3, 1, 1, 3, 3, 2,
-		2, 3, 3, 1, 1, 3, 3, 2,
-		2, 1, 1, 1, 1, 1, 1, 2,
-		2, 1, 1, 1, 1, 1, 1, 2,
-		2, 3, 3, 1, 1, 3, 3, 2,
-		2, 3, 3, 1, 1, 3, 3, 2,
-		2, 2, 2, 2, 2, 2, 2, 2,
-	],
-	[
-		2, 2, 2, 2, 2, 2, 2, 2,
-		2, 4, 4, 4, 4, 5, 5, 2,
-		2, 4, 4, 4, 5, 5, 5, 2,
-		2, 4, 4, 5, 5, 5, 6, 2,
-		2, 4, 5, 5, 5, 6, 6, 2,
-		2, 5, 5, 5, 6, 6, 6, 2,
-		2, 5, 5, 6, 6, 6, 6, 2,
-		2, 2, 2, 2, 2, 2, 2, 2,
-	],
-]
+import { getSheet } from "./sheet.ts";
 
 export const drawSprite = (x: number, y: number, spr: number) => {
+	const {sheet_type, value: sprites} = getSheet(2);
+	if (sheet_type !== "spritesheet") {
+		throw "Trying to run a non-code sheet as code."
+	}
 	setPixelsInRect(x, y, 8, sprites[spr]);
 }
 
diff --git a/index.ts b/index.ts
index 071267c..eb8084a 100644
--- a/index.ts
+++ b/index.ts
@@ -8,6 +8,7 @@ import { refreshKeyboard, keyPressed, K } from "./keyboard.ts";
 import { repl, resetRepl } from "./repl.ts";
 import { addToContext } from "./runcode.ts";
 import { editmode } from "./editmode.ts";
+import { refreshMouse } from "./mouse.ts";
 
 // deno-lint-ignore no-explicit-any
 let game: any = null;
@@ -56,4 +57,5 @@ await mainloop((_t) => {
 		}
 	}
 	refreshKeyboard();
+	refreshMouse();
 });
diff --git a/mouse.ts b/mouse.ts
new file mode 100644
index 0000000..77a368d
--- /dev/null
+++ b/mouse.ts
@@ -0,0 +1,88 @@
+import { WindowMouseEvent } from "https://deno.land/x/dwm@0.3.3/mod.ts";
+import { gameWindow } from "./window.ts";
+
+export const M = {
+	NONE: -1,
+	LEFT: 0,
+	RIGHT: 1,
+	MIDDLE: 2,
+}
+
+const mouseButtonsDown = {
+	[M.LEFT]: false,
+	[M.RIGHT]: false,
+	[M.MIDDLE]: false,
+};
+const mouseEvents: Array<{
+	type: "click" | "down" | "up" | "move",
+	button: typeof M[keyof typeof M],
+	x: number,
+	y: number,
+	prevX?: number,
+	prevY?: number
+}> = [];
+
+let mouseX = 0;
+let mouseY = 0;
+
+const eventPixelCoords = (evt: WindowMouseEvent) => {
+	const {width, height} = gameWindow.size;
+	const pixX = Math.floor(128*evt.clientX/width);
+	const pixY = Math.floor(128*evt.clientY/height);
+	return {
+		x: pixX,
+		y: pixY,
+	}
+}
+
+// addEventListener("dblclick", (evt) => {
+// 	console.log("dblclick", evt.button, evt.clientX, evt.clientY);
+// });
+
+addEventListener("click", (evt) => {
+	mouseEvents.push({type: "click", button: evt.button, ...eventPixelCoords(evt)});
+});
+
+addEventListener("mousedown", (evt) => {
+	mouseButtonsDown[evt.button] = true;
+	mouseEvents.push({type: "down", button: evt.button, ...eventPixelCoords(evt)});
+});
+
+addEventListener("mouseup", (evt) => {
+	mouseButtonsDown[evt.button] = false;
+	mouseEvents.push({type: "up", button: evt.button, ...eventPixelCoords(evt)});
+});
+
+addEventListener("mousemove", (evt) => {
+	const coords = eventPixelCoords(evt);
+	mouseEvents.push({type: "move", button: evt.button, ...eventPixelCoords(evt), prevX: mouseX, prevY: mouseY});
+	mouseX = coords.x;
+	mouseY = coords.y;
+});
+
+export const mousePos = () => {
+	return {
+		x: mouseX,
+		y: mouseY,
+	}
+}
+
+export const getMouseX = () => {
+	return mouseX;
+}
+
+export const getMouseY = () => {
+	return mouseY;
+}
+
+export const refreshMouse = () => {
+	mouseEvents.length = 0;
+}
+
+export const mouseClick = (button: number = M.LEFT) => {
+	return mouseEvents.some(ev => ev.button === button && ev.type === "click");
+}
+
+export const mouseHeld = (button: number = M.LEFT) => {
+	return mouseButtonsDown[button];
+}
\ No newline at end of file
diff --git a/spritetab.ts b/spritetab.ts
index 77365e5..27f7cd2 100644
--- a/spritetab.ts
+++ b/spritetab.ts
@@ -3,9 +3,11 @@ import { fontWidth, fontHeight } from "./font.ts";
 import { drawText, drawSprite } from "./builtins.ts";
 import { COLOR } from "./colors.ts";
 import {getSheet, setSheet} from "./sheet.ts";
+import { mouseClick, mouseHeld, mousePos } from "./mouse.ts";
 
 const state = {
-	selectedIndex: 0,
+	selectedSprite: 0,
+	selectedColor: 0,
 	get sprites() {
 		const {sheet_type, value} = getSheet(2);
 		if (sheet_type !== "spritesheet") {
@@ -18,43 +20,101 @@ const state = {
 	}
 }
 
+const paletteX = 88;
+const paletteY = 12;
+const swatchW = 8;
+const swatchH = 8;
+const paletteW = 4;
+const paletteH = 4;
+
+const spriteX = 8;
+const spriteY = 12;
+const pixelW = 8;
+const pixelH = 8;
+
+const spriteW = 8;
+const spriteH = 8;
+
+const sheetX = 0;
+const sheetY = 88;
+const sheetW = 16;
+const sheetH = 4;
+
+const inRect = (x: number, y: number, rectX: number, rectY: number, rectW: number, rectH: number) => {
+	return (
+		x >= rectX &&
+		x < rectX+rectW &&
+		y >= rectY &&
+		y < rectY+rectH
+	)
+}
+
+const reGrid = (x: number, y: number, gridX: number, gridY: number, cellW: number, cellH: number) => {
+	return {
+		x: Math.floor((x-gridX)/cellW),
+		y: Math.floor((y-gridY)/cellH),
+	}
+}
+
 const update = () => {
+	if (mouseHeld()) {
+		const {x: mouseX, y: mouseY} = mousePos();
+		const inPalette = inRect(mouseX, mouseY, paletteX, paletteY, paletteW*swatchW, paletteH*swatchH);
+		const inSprite = inRect(mouseX, mouseY, spriteX, spriteY, spriteW*pixelW, spriteH*pixelH);
+		const inSheet = inRect(mouseX, mouseY, sheetX, sheetY, sheetW*spriteW, sheetH*spriteH);
+		if (inPalette) {
+			const {x, y} = reGrid(mouseX, mouseY, paletteX, paletteY, swatchW, swatchH);
+			state.selectedColor = paletteW*y+x;
+		}
+		if (inSprite) {
+			const {x, y} = reGrid(mouseX, mouseY, spriteX, spriteY, pixelW, pixelH);
+			const pixelNumber = spriteW*y+x;
+			state.sprites[state.selectedSprite][pixelNumber] = state.selectedColor;
+		}
+		if (inSheet) {
+			const {x, y} = reGrid(mouseX, mouseY, sheetX, sheetY, spriteW, spriteH);
+			state.selectedSprite = sheetW*y+x;
+		}
+	}
 }
 
 const draw = () => {
-	const {sprites, selectedIndex} = state;
+	const {sprites, selectedSprite, selectedColor} = state;
 	clearScreen();
 	fillRect(0, 8, 128, 112, COLOR.BROWN);
+
 	// Draw the palette
-	const paletteX = 88;
-	const paletteY = 12;
-	fillRect(paletteX-1, paletteY-1, 32+2, 32+2, COLOR.BLACK);
+	fillRect(paletteX-1, paletteY-1, (paletteW*swatchW)+2, (paletteH*swatchH)+2, COLOR.BLACK);
 	Object.keys(COLOR).forEach((name, i) => {
-		const swatchX = paletteX+8*(i%4);
-		const swatchY = paletteY+8*Math.floor(i/4);
-		fillRect(swatchX, swatchY, 8, 8, COLOR[name as keyof typeof COLOR]);
+		const swatchX = paletteX+swatchW*(i%paletteW);
+		const swatchY = paletteY+swatchH*Math.floor(i/paletteW);
+		fillRect(swatchX, swatchY, swatchW, swatchH, COLOR[name as keyof typeof COLOR]);
 		if (i === 0) {
 			// transparent
-			Array(64).fill(0).map((_z, j) => {
-				const jx = j%8;
-				const jy = Math.floor(j/8);
+			Array(swatchW*swatchH).fill(0).map((_z, j) => {
+				const jx = j%swatchW;
+				const jy = Math.floor(j/swatchW);
 				setPixelColor(swatchX+jx, swatchY+jy, (jx+jy)%2 ? COLOR.BLACK : COLOR.WHITE);
 			})
 		}
+		if (i === selectedColor) {
+			fillRect(swatchX, swatchY, swatchW, 1, COLOR.WHITE);
+			fillRect(swatchX, swatchY, 1, swatchH, COLOR.WHITE);
+			fillRect(swatchX+swatchW-1, swatchY, 1, swatchH, COLOR.WHITE);
+			fillRect(swatchX, swatchY+swatchH-1, swatchW, 1, COLOR.WHITE);
+		}
 	});
+
 	// Draw the current sprite
-	const spriteX = 8;
-	const spriteY = 12;
-	fillRect(spriteX-1, spriteY-1, 64+2, 64+2, COLOR.BLACK);
-	sprites[selectedIndex].forEach((pix, i) => {
-		fillRect(spriteX+8*(i%8), spriteY+8*Math.floor(i/8), 8, 8, pix);
+	fillRect(spriteX-1, spriteY-1, (spriteW*pixelW)+2, (spriteH*pixelH)+2, COLOR.BLACK);
+	sprites[selectedSprite].forEach((pix, i) => {
+		fillRect(spriteX+pixelW*(i%spriteW), spriteY+pixelH*Math.floor(i/spriteW), pixelW, pixelH, pix);
 	});
+
 	// Draw the spritesheet
-	const sheetX = 0;
-	const sheetY = 88;
-	fillRect(sheetX, sheetY-1, 128, 64+1, COLOR.BLACK);
+	fillRect(sheetX, sheetY-1, (sheetW*spriteW), (sheetH*spriteH)+1, COLOR.BLACK);
 	sprites.forEach((_sprite, i) => {
-		drawSprite(sheetX+8*(i%16), sheetY+8*Math.floor(i/16), i);
+		drawSprite(sheetX+spriteW*(i%sheetW), sheetY+spriteH*Math.floor(i/sheetW), i);
 	});
 }
 
diff --git a/window.ts b/window.ts
index 28da5d8..7a13b55 100644
--- a/window.ts
+++ b/window.ts
@@ -6,7 +6,7 @@ import {
 export {mainloop} from "./deps.ts";
 import { palette } from "./colors.ts";
 
-const window = createWindow({
+export const gameWindow = createWindow({
 	title: "Faux",
 	width: 1024,
 	height: 1024,
@@ -160,5 +160,5 @@ export const frame = () => {
 	gl.EnableVertexAttribArray(0);
 	gl.EnableVertexAttribArray(1);
 	gl.DrawArrays(gl.TRIANGLES, 0, 6*pixelsPerRow*pixelsPerRow);
-	window.swapBuffers();
+	gameWindow.swapBuffers();
 }