diff --git a/editor/src/debug/mod.rs b/editor/src/debug/mod.rs
new file mode 100644
index 0000000000..6c7d25bb33
--- /dev/null
+++ b/editor/src/debug/mod.rs
@@ -0,0 +1,52 @@
+use crate::game::{GameState, Mode};
+use ezgui::{EventCtx, EventLoopMode, GfxCtx, Wizard};
+use std::collections::HashMap;
+
+pub struct DebugMode {
+    state: State,
+}
+
+enum State {
+    Exploring,
+}
+
+impl DebugMode {
+    pub fn new() -> DebugMode {
+        DebugMode {
+            state: State::Exploring,
+        }
+    }
+
+    pub fn event(state: &mut GameState, ctx: &mut EventCtx) -> EventLoopMode {
+        match state.mode {
+            Mode::Debug(ref mut mode) => {
+                ctx.canvas.handle_event(ctx.input);
+                state.ui.state.primary.current_selection =
+                    state
+                        .ui
+                        .handle_mouseover(ctx, None, &state.ui.state.primary.sim);
+
+                ctx.input.set_mode("Debug Mode", ctx.canvas);
+                if ctx.input.modal_action("quit") {
+                    state.mode = Mode::SplashScreen(Wizard::new(), None);
+                }
+
+                EventLoopMode::InputOnly
+            }
+            _ => unreachable!(),
+        }
+    }
+
+    pub fn draw(state: &GameState, g: &mut GfxCtx) {
+        match state.mode {
+            Mode::Debug(ref mode) => match mode.state {
+                State::Exploring => {
+                    state
+                        .ui
+                        .new_draw(g, None, HashMap::new(), &state.ui.state.primary.sim);
+                }
+            },
+            _ => unreachable!(),
+        }
+    }
+}
diff --git a/editor/src/game.rs b/editor/src/game.rs
index aa095c58bf..3c753556ff 100644
--- a/editor/src/game.rs
+++ b/editor/src/game.rs
@@ -1,3 +1,4 @@
+use crate::debug::DebugMode;
 use crate::edit::EditMode;
 use crate::sandbox::SandboxMode;
 use crate::state::{Flags, UIState};
@@ -28,6 +29,7 @@ pub enum Mode {
     Edit(EditMode),
     Tutorial(TutorialMode),
     Sandbox(SandboxMode),
+    Debug(DebugMode),
 }
 
 impl GameState {
@@ -35,7 +37,7 @@ impl GameState {
         let splash = !flags.no_splash;
         let mut rng = flags.sim_flags.make_rng();
         let mut game = GameState {
-            mode: Mode::Legacy,
+            mode: Mode::Sandbox(SandboxMode::new()),
             ui: UI::new(UIState::new(flags, prerender, true), canvas),
         };
         if splash {
@@ -87,6 +89,7 @@ impl GUI for GameState {
             Mode::Edit(_) => EditMode::event(self, ctx),
             Mode::Tutorial(_) => TutorialMode::event(self, ctx),
             Mode::Sandbox(_) => SandboxMode::event(self, ctx),
+            Mode::Debug(_) => DebugMode::event(self, ctx),
         }
     }
 
@@ -100,6 +103,7 @@ impl GUI for GameState {
             Mode::Edit(_) => EditMode::draw(self, g),
             Mode::Tutorial(_) => TutorialMode::draw(self, g),
             Mode::Sandbox(_) => SandboxMode::draw(self, g),
+            Mode::Debug(_) => DebugMode::draw(self, g),
         }
     }
 
@@ -172,6 +176,7 @@ fn splash_screen(
     let load_map = "Load another map";
     let edit = "Edit map";
     let tutorial = "Tutorial";
+    let debug = "Debug mode";
     let legacy = "Legacy mode (ignore this)";
     let about = "About";
     let quit = "Quit";
@@ -181,7 +186,9 @@ fn splash_screen(
         match wizard
             .choose_string(
                 "Welcome to A/B Street!",
-                vec![sandbox, load_map, edit, tutorial, legacy, about, quit],
+                vec![
+                    sandbox, load_map, edit, tutorial, debug, legacy, about, quit,
+                ],
             )?
             .as_str()
         {
@@ -214,6 +221,7 @@ fn splash_screen(
                     ctx.canvas.center_to_map_pt(),
                 )))
             }
+            x if x == debug => break Some(Mode::Debug(DebugMode::new())),
             x if x == legacy => break Some(Mode::Legacy),
             x if x == about => {
                 if wizard.acknowledge(LogScroller::new(
diff --git a/editor/src/main.rs b/editor/src/main.rs
index cc1236d032..6fa5c648a0 100644
--- a/editor/src/main.rs
+++ b/editor/src/main.rs
@@ -1,4 +1,5 @@
 mod colors;
+mod debug;
 mod edit;
 mod game;
 mod objects;
diff --git a/editor/src/ui.rs b/editor/src/ui.rs
index b8a749fd92..0995149cdf 100644
--- a/editor/src/ui.rs
+++ b/editor/src/ui.rs
@@ -174,6 +174,7 @@ impl GUI for UI {
                     (Key::Dot, "forwards"),
                 ],
             ),
+            ModalMenu::new("Debug Mode", vec![(Key::Escape, "quit")]),
         ]
     }