Index: binaries/data/config/default.cfg
===================================================================
--- binaries/data/config/default.cfg
+++ binaries/data/config/default.cfg
@@ -151,6 +151,7 @@
 silhouettes = "Alt+Shift+S"              ; Toggle unit silhouettes
 showsky = "Alt+Z"                        ; Toggle sky
 summary = "Ctrl+Tab"                     ; Toggle in-game summary
+options.toggle = "Alt+O"                 ; Toggle options window
 
 ; > CLIPBOARD CONTROLS
 copy = "Ctrl+C"                       ; Copy to clipboard
Index: binaries/data/mods/public/gui/common/functions_global_object.js
===================================================================
--- binaries/data/mods/public/gui/common/functions_global_object.js
+++ binaries/data/mods/public/gui/common/functions_global_object.js
@@ -4,6 +4,11 @@
 var g_MessageBoxBtnFunctions = [];
 var g_MessageBoxCallbackArgs = [];
 
+/*
+ * Identifier whether the Options window is shown.
+ */
+var g_OptionsShown = false;
+
 var g_MessageBoxCallbackFunction = function(btnCode)
 {
 	if (btnCode !== undefined && g_MessageBoxBtnFunctions[btnCode])
@@ -156,3 +161,14 @@
 		"mapSettings": Engine.GetInitAttributes().settings
 	};
 }
+
+function showOptions()
+{
+	if (!g_OptionsShown)
+		Engine.PushGuiPage("page_options.xml");
+}
+
+function setOptionsHotkey(func)
+{
+	Engine.GetGUIObjectByName("hotkey.options.toggle").onpress = func || (() => showOptions());
+}
Index: binaries/data/mods/public/gui/common/global.xml
===================================================================
--- binaries/data/mods/public/gui/common/global.xml
+++ binaries/data/mods/public/gui/common/global.xml
@@ -14,6 +14,13 @@
 
 		<!--
 		==========================================
+		- HOTKEY OBJECTS
+		==========================================
+		-->
+		<object hotkey="options.toggle" name="hotkey.options.toggle" />
+
+		<!--
+		==========================================
 		- GAMESTATE NOTIFICATIONS
 		==========================================
 		-->
Index: binaries/data/mods/public/gui/lobby/lobby.js
===================================================================
--- binaries/data/mods/public/gui/lobby/lobby.js
+++ binaries/data/mods/public/gui/lobby/lobby.js
@@ -401,6 +401,7 @@
 	// Get all messages since the login
 	for (let msg of Engine.LobbyGuiPollHistoricMessages())
 		g_NetMessageTypes[msg.type][msg.level](msg);
+	setOptionsHotkey();
 }
 
 function updateLobbyColumns()
Index: binaries/data/mods/public/gui/manual/intro.txt
===================================================================
--- binaries/data/mods/public/gui/manual/intro.txt
+++ binaries/data/mods/public/gui/manual/intro.txt
@@ -49,6 +49,7 @@
 Shift + F11: Save current profiler data to "logs/profile.txt"
 F2: Take screenshot (in .png format, location is displayed in the top left of the GUI after the file has been saved, and can also be seen in the console/logs if you miss it there)
 Shift + F2: Take huge screenshot (6400px*4800px, in .bmp format, location is displayed in the top left of the GUI after the file has been saved, and can also be seen in the console/logs if you miss it there)
+Alt + O: Toggle options window.
 Alt + S: Switch to the next tab.
 Alt + W: Switch to the previous tab.
 
Index: binaries/data/mods/public/gui/options/options.js
===================================================================
--- binaries/data/mods/public/gui/options/options.js
+++ binaries/data/mods/public/gui/options/options.js
@@ -141,6 +141,8 @@
 
 function init(data, hotloadData)
 {
+	g_OptionsShown = true;
+
 	g_HasCallback = hotloadData && hotloadData.callback || data && data.callback;
 	g_SelectedCategory = hotloadData ? hotloadData.selectedCategory : 0;
 
@@ -150,6 +152,7 @@
 
 	placeTabButtons();
 	displayOptions();
+	setOptionsHotkey(closePage);
 }
 
 function getHotloadData()
@@ -386,8 +389,12 @@
 			500, 200,
 			translate("You have unsaved changes, do you want to close this window?"),
 			translate("Warning"),
-			[translate("No"), translate("Yes")],
-			[null, closePageWithoutConfirmation]);
+			[translate("No"), translate("Keep temporary and close"), translate("Save and close")],
+			[null, closePageWithoutConfirmation, () => {
+				saveChanges();
+				closePageWithoutConfirmation();
+			}]
+		);
 	else
 		closePageWithoutConfirmation();
 }
@@ -398,4 +405,5 @@
 		Engine.PopGuiPageCB();
 	else
 		Engine.PopGuiPage();
+	g_OptionsShown = false;
 }
Index: binaries/data/mods/public/gui/page_replaymenu.xml
===================================================================
--- binaries/data/mods/public/gui/page_replaymenu.xml
+++ binaries/data/mods/public/gui/page_replaymenu.xml
@@ -8,6 +8,8 @@
 	<include>common/sprites.xml</include>
 	<include>common/styles.xml</include>
 
+	<include>common/global.xml</include>
+
 	<include>replaymenu/sprites.xml</include>
 	<include>replaymenu/replay_menu.xml</include>
 </page>
Index: binaries/data/mods/public/gui/pregame/mainmenu.js
===================================================================
--- binaries/data/mods/public/gui/pregame/mainmenu.js
+++ binaries/data/mods/public/gui/pregame/mainmenu.js
@@ -38,6 +38,7 @@
 		guiObj.sprite = g_BackgroundLayerset[i].sprite;
 		guiObj.z = i;
 	}
+	setOptionsHotkey();
 }
 
 function getHotloadData()
Index: binaries/data/mods/public/gui/session/session.js
===================================================================
--- binaries/data/mods/public/gui/session/session.js
+++ binaries/data/mods/public/gui/session/session.js
@@ -300,6 +300,7 @@
 		g_Selection.selected = hotloadData.selection;
 
 	initChatWindow();
+	setOptionsHotkey();
 
 	sendLobbyPlayerlistUpdate();
 	onSimulationUpdate();