diff --git a/src/main.js b/src/main.js
index fb647ca..9173146 100644
--- a/src/main.js
+++ b/src/main.js
@@ -6,16 +6,22 @@ const os = require("node:os");
 const child_process = require("node:child_process");
 const electron = require("electron");
 
+const update = require(path.join(__dirname, "update.js"));
+
 let configFilePath;
+let plutoniumInstallDirectory;
 switch (os.platform()) {
 	case "win32":
 		configFilePath = path.join(process.env["LOCALAPPDATA"], "Plutonium", "open-plutonium-launcher.json");
+		plutoniumInstallDirectory = path.join(process.env["LOCALAPPDATA"], "Plutonium");
 		break;
 	case "linux":
 		configFilePath = path.join(os.userInfo().homedir, ".config", "open-plutonium-launcher.json");
+		plutoniumInstallDirectory = path.join(os.userInfo().homedir, ".local", "share", "Plutonium");
 		break;
 	case "darwin":
 		configFilePath = path.join(os.userInfo().homedir, "Library", "Application Support", "open-plutonium-launcher.json");
+		plutoniumInstallDirectory = path.join(os.userInfo().homedir, "Library", "Application Support", "Plutonium");
 		break;
 	default:
 		electron.dialog.showErrorBox("Incompatible system", "Sorry, your operating system doesn't seem to be supported...");
@@ -93,6 +99,101 @@ function fetchPlutoniumManifest() {
 	});
 }
 
+function getPlutoniumSession(game, token) {
+	return new Promise(function (resolve, reject) {
+		let payload = JSON.stringify({
+			"game": game
+		});
+
+		let request = https.request("https://nix.plutonium.pw/api/auth/session", {
+			"method": "POST",
+			"headers": {
+				"Content-Type": "application/json",
+				"Content-Length": payload.length,
+				"Authorization": "UserToken " + token,
+				"X-Plutonium-Revision": String(plutoniumManifest.revision),
+				"User-Agent": "Nix/3.0"
+			}
+		}, function (response) {
+			if (response.statusCode !== 200) {
+				return resolve({
+					"status": "unauthenticated",
+					"successful": false
+				});
+			}
+
+			response.setEncoding("utf-8");
+
+			let body = "";
+			response.on("data", function (chunk) {
+				body += chunk;
+			});
+			response.on("end", function () {
+				try {
+					let data = JSON.parse(body);
+
+					if (!("token" in data)) {
+						reject(new Error("Authentication seems to be successful but no token was returned."));
+					}
+
+					resolve({
+						"status": "authenticated",
+						"successful": true,
+						...data
+					});
+
+					userInfo = data;
+
+					mainWindow.loadFile(path.join(__dirname, "src", "views", "games.html"));
+				} catch (error) {
+					reject(error);
+				}
+			});
+		});
+
+		request.on("error", function (error) {
+			reject(error);
+		});
+
+		request.write(payload);
+		request.end();
+	});
+}
+
+function launch(plutoniumInstallDirectory, game, gameInstallDirectory, online) {
+	return new Promise(function (resolve, reject) {
+		getPlutoniumSession(game, userInfo.token).then(function (data) {
+			if (!data.successful) {
+				return reject(new Error("Authentication has failed."));
+			}
+
+			let bootstrapperBinary = path.join(plutoniumInstallDirectory, "bin", "plutonium-bootstrapper-win32.exe");
+			let bootstrapperArguments = [game, gameInstallDirectory];
+
+			if (online) {
+				bootstrapperArguments.push("-token");
+				bootstrapperArguments.push(data.token);
+			} else {
+				bootstrapperArguments.push("+name");
+				bootstrapperArguments.push(userInfo.username);
+				bootstrapperArguments.push("-lan");
+			}
+
+			let gameProcess = child_process.spawn(bootstrapperBinary, bootstrapperArguments, {
+				"detached": true,
+				"stdio": "ignore"
+			});
+
+			gameProcess.on("spawn", function () {
+				resolve(true);
+			});
+			gameProcess.on("error", function (error) {
+				reject(error);
+			});
+		});
+	});
+}
+
 electron.app.once("ready", function () {
 	createMainWindow();
 	fetchPlutoniumManifest().then(function (manifest) {
@@ -167,3 +268,28 @@ electron.ipcMain.handle("login", function (event, username, password) {
 		request.end();
 	});
 });
+
+electron.ipcMain.handle("launch", function (event, game, online = true) {
+	return new Promise(function (resolve, reject) {
+		if (!(game in config.gameDirectories)) {
+			return resolve(false);
+		}
+		let gameInstallDirectory = config.gameDirectories[game];
+
+		update.checkFiles(plutoniumManifest, plutoniumInstallDirectory).then(function (fileList) {
+			let filesToUpdate = fileList.filter(function (file) {
+				return !file.ok;
+			});
+
+			update.downloadFiles(plutoniumInstallDirectory, plutoniumManifest.baseUrl, filesToUpdate).then(function () {
+				launch(plutoniumInstallDirectory, game, gameInstallDirectory, online).then(function (result) {
+					resolve(result);
+				});
+			}).catch(function (error) {
+				reject(error);
+			});
+		}).catch(function (error) {
+			reject(error);
+		});
+	});
+});
diff --git a/src/update.js b/src/update.js
index 2524d8a..f9233bc 100644
--- a/src/update.js
+++ b/src/update.js
@@ -63,25 +63,37 @@ function processDownloadQueue(baseDirectory, baseURL, fileEntries) {
 		let queue = [...fileEntries];
 
 		let finishCallback = function () {
-			if (queue.length > 0) {
+			runningDownloads--;
 
+			if (queue.length > 0 && runningDownloads < module.exports.concurrentDownloads) {
+				let currentEntry = queue.shift();
+
+				downloadFile(baseURL + currentEntry.hash, path.join(baseDirectory, currentEntry.name)).then(finishCallback).catch((errorCallback).bind(currentEntry));
+			} else {
+				resolve();
 			}
 		};
 
+		let errorCallback = function (error) {
+			runningDownloads--;
+
+			if (!this.retries) {
+				this.retries = 0;
+			}
+			if (this.retries > 3) return reject(error);
+
+			this.retries++;
+			queue.push(this);
+		};
+
 		for (let d = 0; d < module.exports.concurrentDownloads; d++) {
 			if (queue.length < 1) break;
 
 			let currentEntry = queue.shift();
 
-			downloadFile(baseURL + currentEntry.hash, path.join(baseDirectory, currentEntry.name)).then(finishCallback).catch((function (error) {
-				if (!this.retries) {
-					this.retries = 0;
-				}
-				if (this.retries > 3) return reject(error);
+			runningDownloads++;
 
-				this.retries++;
-				queue.push(this);
-			}).bind(currentEntry));
+			downloadFile(baseURL + currentEntry.hash, path.join(baseDirectory, currentEntry.name)).then(finishCallback).catch((errorCallback).bind(currentEntry));
 		}
 	});
 }
@@ -107,9 +119,15 @@ module.exports = {
 	},
 	"downloadFiles": function (baseDirectory, baseURL, fileEntries) {
 		return new Promise(function (resolve, reject) {
-			processDownloadQueue(baseDirectory, baseURL, fileEntries.filter(function (entry) {
+			let filesToProcess = fileEntries.filter(function (entry) {
 				return !entry.ok;
-			})).then(function () {
+			});
+
+			if (filesToProcess.length < 1) {
+				return resolve(true);
+			}
+
+			processDownloadQueue(baseDirectory, baseURL, filesToProcess).then(function () {
 				resolve(true);
 			}).catch(function (error) {
 				reject(error);