diff --git a/frontend/public/games/jump-counter/script.js b/frontend/public/games/jump-counter/script.js
index 2e8c225b..69c0662d 100644
--- a/frontend/public/games/jump-counter/script.js
+++ b/frontend/public/games/jump-counter/script.js
@@ -90,7 +90,7 @@ function createObstacle() {
 
     const moveObstacle = setInterval(() => {
         if (gamePaused) return;
-        let obstacleLeft = parseInt(obstacle.style.left);
+        let obstacleLeft = parseInt(obstacle.style.left, 10);
         if (obstacleLeft <= -40) {
             obstacle.remove();
             obstacles.shift();
diff --git a/frontend/public/scripts/simon.js b/frontend/public/scripts/simon.js
index 7afed7fc..85df0fe7 100644
--- a/frontend/public/scripts/simon.js
+++ b/frontend/public/scripts/simon.js
@@ -2,7 +2,7 @@
 let sequence = [];
 let playerSequence = [];
 let level = 1;
-let highScore = parseInt(localStorage.getItem('simonHighScore')) || 0;
+let highScore = parseInt(localStorage.getItem('simonHighScore', 10)) || 0;
 let gameActive = false;
 let showingSequence = false;
 let inputLocked = false;
diff --git a/frontend/public/scripts/sudoku.js b/frontend/public/scripts/sudoku.js
index 72c98737..815de8fd 100644
--- a/frontend/public/scripts/sudoku.js
+++ b/frontend/public/scripts/sudoku.js
@@ -104,7 +104,7 @@ function handleKeyPress(e) {
 
     const key = e.key;
     if (key >= '1' && key <= '9') {
-        inputNumber(parseInt(key));
+        inputNumber(parseInt(key, 10));
     } else if (key === 'Delete' || key === 'Backspace') {
         clearCell();
     }
diff --git a/frontend/public/scripts/tic-tac-toe.js b/frontend/public/scripts/tic-tac-toe.js
index be2c8d51..c17e0570 100644
--- a/frontend/public/scripts/tic-tac-toe.js
+++ b/frontend/public/scripts/tic-tac-toe.js
@@ -17,7 +17,7 @@ function saveScore(score) {
 let board = ['', '', '', '', '', '', '', '', ''];
 let currentPlayer = 'X';
 let gameActive = true;
-let scores = JSON.parse(localStorage.getItem('ticTacToeScores')) || { x: 0, o: 0, draws: 0 };
+let scores = (JSON.parse(localStorage.getItem('ticTacToeScores') ?? "null") ?? null) || { x: 0, o: 0, draws: 0 };
 
 // Winning combinations
 const winningConditions = [