rolandjlevy/js-sliders-game — reverse-engineered prompt

Build me a simple browser puzzle game like the classic sliding numbers game. I want the player to pick a board size like 3 by 3 or 4 by 4, then move numbered tiles into the empty space until all the numbers are in order. Show a move counter, make tiles turn green when they’re in the correct spot, and have a clear win state when the puzzle is solved.

Keep it lightweight with plain JavaScript, HTML, and CSS, no big framework needed. It should work nicely on phones and desktop. Add a help section that explains how to play, and make sure each new game starts shuffled in a playable way.

After someone wins, let them enter their name and save their score to a leaderboard. Use a small serverless API setup for the leaderboard, with MongoDB if needed, and make sure user input is sanitized so nobody can inject bad HTML. Include everything needed to run locally and deploy on Vercel.