diff --git a/src/core/PatternDecoder.ts b/src/core/PatternDecoder.ts
index 1311aec44..c749b1615 100644
--- a/src/core/PatternDecoder.ts
+++ b/src/core/PatternDecoder.ts
@@ -5,10 +5,7 @@ export class PatternDecoder {
   readonly width: number;
   readonly scale: number;
 
-  constructor(
-    base64: string,
-    base64urlDecode: (input: Uint8Array | string) => Uint8Array,
-  ) {
+  constructor(base64: string, base64urlDecode: (input: string) => Uint8Array) {
     this.bytes = base64urlDecode(base64);
 
     if (this.bytes.length < 3) {
diff --git a/src/core/game/Game.ts b/src/core/game/Game.ts
index 5c50d07c3..88babd8a2 100644
--- a/src/core/game/Game.ts
+++ b/src/core/game/Game.ts
@@ -84,6 +84,8 @@ export enum GameMapType {
   Italia = "Italia",
 }
 
+export type GameMapName = keyof typeof GameMapType;
+
 export const mapCategories: Record<string, GameMapType[]> = {
   continental: [
     GameMapType.World,
diff --git a/src/server/Archive.ts b/src/server/Archive.ts
index 9f5cfc6b5..6b3675d94 100644
--- a/src/server/Archive.ts
+++ b/src/server/Archive.ts
@@ -35,11 +35,20 @@ export async function archive(gameRecord: GameRecord) {
       );
       await archiveFullGameToR2(gameRecord);
     }
-  } catch (error) {
+  } catch (error: unknown) {
+    // If the error is not an instance of Error, log it as a string
+    if (!(error instanceof Error)) {
+      log.error(
+        `${gameRecord.info.gameID}: Final archive error. Non-Error type: ${String(error)}`,
+      );
+      return;
+    }
+
+    const { message, stack, name } = error;
     log.error(`${gameRecord.info.gameID}: Final archive error: ${error}`, {
-      message: error?.message ?? error,
-      stack: error?.stack,
-      name: error?.name,
+      message: message,
+      stack: stack,
+      name: name,
       ...(error && typeof error === "object" ? error : {}),
     });
   }
@@ -68,11 +77,20 @@ async function archiveAnalyticsToR2(gameRecord: GameRecord) {
     });
 
     log.info(`${info.gameID}: successfully wrote game analytics to R2`);
-  } catch (error) {
+  } catch (error: unknown) {
+    // If the error is not an instance of Error, log it as a string
+    if (!(error instanceof Error)) {
+      log.error(
+        `${gameRecord.info.gameID}: Error writing game analytics to R2. Non-Error type: ${String(error)}`,
+      );
+      return;
+    }
+
+    const { message, stack, name } = error;
     log.error(`${info.gameID}: Error writing game analytics to R2: ${error}`, {
-      message: error?.message ?? error,
-      stack: error?.stack,
-      name: error?.name,
+      message: message,
+      stack: stack,
+      name: name,
       ...(error && typeof error === "object" ? error : {}),
     });
     throw error;
@@ -116,12 +134,20 @@ export async function readGameRecord(
     if (response.Body === undefined) return null;
     const bodyContents = await response.Body.transformToString();
     return JSON.parse(bodyContents) as GameRecord;
-  } catch (error) {
+  } catch (error: unknown) {
+    // If the error is not an instance of Error, log it as a string
+    if (!(error instanceof Error)) {
+      log.error(
+        `${gameId}: Error reading game record from R2. Non-Error type: ${String(error)}`,
+      );
+      return null;
+    }
+    const { message, stack, name } = error;
     // Log the error for monitoring purposes
     log.error(`${gameId}: Error reading game record from R2: ${error}`, {
-      message: error?.message ?? error,
-      stack: error?.stack,
-      name: error?.name,
+      message: message,
+      stack: stack,
+      name: name,
       ...(error && typeof error === "object" ? error : {}),
     });
 
@@ -137,14 +163,22 @@ export async function gameRecordExists(gameId: GameID): Promise<boolean> {
       Key: `${gameFolder}/${gameId}`, // Fixed - needed to include gameFolder
     });
     return true;
-  } catch (error) {
-    if (error.name === "NotFound") {
+  } catch (error: unknown) {
+    // If the error is not an instance of Error, log it as a string
+    if (!(error instanceof Error)) {
+      log.error(
+        `${gameId}: Error checking archive existence. Non-Error type: ${String(error)}`,
+      );
+      return false;
+    }
+    const { message, stack, name } = error;
+    if (name === "NotFound") {
       return false;
     }
     log.error(`${gameId}: Error checking archive existence: ${error}`, {
-      message: error?.message ?? error,
-      stack: error?.stack,
-      name: error?.name,
+      message: message,
+      stack: stack,
+      name: name,
       ...(error && typeof error === "object" ? error : {}),
     });
     return false;
diff --git a/src/server/GameServer.ts b/src/server/GameServer.ts
index 76e7615b0..1f4956b19 100644
--- a/src/server/GameServer.ts
+++ b/src/server/GameServer.ts
@@ -46,13 +46,14 @@ export class GameServer {
   private _hasStarted = false;
   private _startTime: number | null = null;
 
-  private endTurnIntervalID;
+  private endTurnIntervalID: ReturnType<typeof setInterval> | undefined;
 
   private lastPingUpdate = 0;
 
   private winner: ClientSendWinnerMessage | null = null;
 
-  private gameStartInfo: GameStartInfo;
+  // Note: This can be undefined if accessed before the game starts.
+  private gameStartInfo!: GameStartInfo;
 
   private log: Logger;
 
@@ -402,7 +403,9 @@ export class GameServer {
 
   async end() {
     // Close all WebSocket connections
-    clearInterval(this.endTurnIntervalID);
+    if (this.endTurnIntervalID) {
+      clearInterval(this.endTurnIntervalID);
+    }
     this.allClients.forEach((client) => {
       client.ws.removeAllListeners("message");
       if (client.ws.readyState === WebSocket.OPEN) {
diff --git a/src/server/Logger.ts b/src/server/Logger.ts
index 94e508fbb..16c3496b2 100644
--- a/src/server/Logger.ts
+++ b/src/server/Logger.ts
@@ -24,7 +24,7 @@ const loggerProvider = new LoggerProvider({
 if (config.env() === GameEnv.Prod && config.otelEnabled()) {
   console.log("OTEL enabled");
   // Configure OpenTelemetry endpoint with basic auth (if provided)
-  const headers = {};
+  const headers: Record<string, string> = {};
   if (config.otelUsername() && config.otelPassword()) {
     headers["Authorization"] =
       "Basic " +
diff --git a/src/server/MapPlaylist.ts b/src/server/MapPlaylist.ts
index 49c832f9c..66ab8cacb 100644
--- a/src/server/MapPlaylist.ts
+++ b/src/server/MapPlaylist.ts
@@ -2,6 +2,7 @@ import { getServerConfigFromServer } from "../core/configuration/ConfigLoader";
 import {
   Difficulty,
   Duos,
+  GameMapName,
   GameMapType,
   GameMode,
   GameType,
@@ -17,7 +18,9 @@ const log = logger.child({});
 
 const config = getServerConfigFromServer();
 
-const frequency = {
+// How many times each map should appear in the playlist.
+// Note: The Partial should eventually be removed for better type safety.
+const frequency: Partial<Record<GameMapName, number>> = {
   World: 3,
   Europe: 2,
   Africa: 2,
@@ -27,7 +30,6 @@ const frequency = {
   GatewayToTheAtlantic: 1,
   Iceland: 1,
   SouthAmerica: 1,
-  KnownWorld: 1,
   DeglaciatedAntarctica: 1,
   EuropeClassic: 1,
   Mena: 1,
@@ -109,8 +111,8 @@ export class MapPlaylist {
 
   private shuffleMapsPlaylist(): boolean {
     const maps: GameMapType[] = [];
-    Object.keys(GameMapType).forEach((key) => {
-      for (let i = 0; i < parseInt(frequency[key]); i++) {
+    (Object.keys(GameMapType) as GameMapName[]).forEach((key) => {
+      for (let i = 0; i < (frequency[key] ?? 0); i++) {
         maps.push(GameMapType[key]);
       }
     });
diff --git a/src/server/WorkerMetrics.ts b/src/server/WorkerMetrics.ts
index 1576b0f73..9c2071bb9 100644
--- a/src/server/WorkerMetrics.ts
+++ b/src/server/WorkerMetrics.ts
@@ -18,7 +18,7 @@ export function initWorkerMetrics(gameManager: GameManager): void {
   const resource = getOtelResource();
 
   // Configure auth headers
-  const headers = {};
+  const headers: Record<string, string> = {};
   if (config.otelEnabled()) {
     headers["Authorization"] =
       "Basic " +