diff --git a/app/CMakeLists.txt b/app/CMakeLists.txt
index f75e8a4..3f5fc9d 100644
--- a/app/CMakeLists.txt
+++ b/app/CMakeLists.txt
@@ -5,6 +5,7 @@ set_default_target_options(game)
 target_include_directories(game PUBLIC include)
 
 target_link_libraries(game PRIVATE
+  m
   LibXml2::LibXml2
   SDL2::SDL2
   SDL2::SDL2main
diff --git a/app/main.c b/app/main.c
index 2b60e71..05973cb 100644
--- a/app/main.c
+++ b/app/main.c
@@ -8,6 +8,8 @@
 #include <assert.h>
 #include <ctype.h>
 #include <libxml/parser.h>
+#include <math.h>
+#include <stdbool.h>
 #include <string.h>
 
 #define SCALE 4
@@ -32,12 +34,28 @@
 #define PIHEIGHT 64
 #define PIANIMLEN 8
 
+#define WALKSPEED 72 // pixels per second
+
 #define BASEANIMPERIOD 200
 
+typedef struct {
+	bool left, right, up, down;
+} input_state_t;
+
+typedef struct {
+	double x, y;
+} dvec_t;
+
 static SDL_Window *window;
 static SDL_Renderer *renderer;
 static unsigned map[MAPWIDTH][MAPHEIGHT];
 static SDL_Texture *tstex, *pitex;
+static input_state_t input;
+
+static inline double mag(dvec_t v)
+{
+	return sqrt(v.x * v.x + v.y * v.y);
+}
 
 int main(int argc, char *argv[])
 {
@@ -144,25 +162,77 @@ int main(int argc, char *argv[])
 	assert(NULL != pitex);
 
 	int offx = 16, offy = 0;
-	const SDL_Rect pdest = {
-		.x = SCALE * 80,
-		.y = SCALE * 80,
-		.w = SCALE * PIWIDTH,
-		.h = SCALE * PIHEIGHT,
-	};
+	SDL_Rect psrc = { .y = 0, .w = PIWIDTH, .h = PIHEIGHT };
+	SDL_Rect pdest = { .w = SCALE * PIWIDTH, .h = SCALE * PIHEIGHT };
+	dvec_t pvel = { 0, 0 }, ppos = { 80, 80 };
 
 	SDL_Event event;
+	uint64_t prevt = SDL_GetTicks64();
 	while (1) {
+		// Calculate dt
+		const uint64_t t = SDL_GetTicks64();
+		const uint64_t dt = t - prevt;
+		prevt = t;
+
 		// Handle events
 		SDL_PollEvent(&event);
 		switch (event.type) {
 		case SDL_QUIT:
 			goto quit;
 
+		case SDL_KEYDOWN:
+			switch (event.key.keysym.sym) {
+			case SDLK_LEFT:
+				input.left = true;
+				break;
+			case SDLK_RIGHT:
+				input.right = true;
+				break;
+			case SDLK_UP:
+				input.up = true;
+				break;
+			case SDLK_DOWN:
+				input.down = true;
+				break;
+			default:
+				break;
+			}
+			break;
+
+		case SDL_KEYUP:
+			switch (event.key.keysym.sym) {
+			case SDLK_LEFT:
+				input.left = false;
+				break;
+			case SDLK_RIGHT:
+				input.right = false;
+				break;
+			case SDLK_UP:
+				input.up = false;
+				break;
+			case SDLK_DOWN:
+				input.down = false;
+				break;
+			default:
+				break;
+			}
+			break;
+
 		default:
 			break;
 		}
 
+		// Calculate and apply velocity
+		pvel.x = (input.left ? -1 : 0) + (input.right ? 1 : 0);
+		pvel.y = (input.up ? -1 : 0) + (input.down ? 1 : 0);
+		const double pspeed = mag(pvel);
+		if (pspeed != 0) {
+			pvel.x *= WALKSPEED / pspeed;
+			pvel.y *= WALKSPEED / pspeed;
+			ppos.x += (double)dt / 1000.0 * pvel.x;
+			ppos.y += (double)dt / 1000.0 * pvel.y;
+		}
+
 		SDL_RenderClear(renderer);
 
 		// Draw map
@@ -189,14 +259,10 @@ int main(int argc, char *argv[])
 		}
 
 		// Draw player
-		const unsigned piframe
-		    = (SDL_GetTicks64() / BASEANIMPERIOD) % PIANIMLEN;
-		const SDL_Rect psrc = {
-			.x = PIWIDTH * piframe,
-			.y = 0,
-			.w = PIWIDTH,
-			.h = PIHEIGHT,
-		};
+		const unsigned piframe = (t / BASEANIMPERIOD) % PIANIMLEN;
+		psrc.x = PIWIDTH * piframe;
+		pdest.x = SCALE * (int)ppos.x;
+		pdest.y = SCALE * (int)ppos.y;
 		SDL_RenderCopy(renderer, pitex, &psrc, &pdest);
 
 		SDL_RenderPresent(renderer);