Deep Merge Physics Puzzle Game

Builds a complete physics merge game in a single HTML file. No libraries or images needed. Drop sea creatures into a glass aquarium. Two of the same kind merge into the next bigger one, from a tiny shell all the way up to a whale. Includes realistic stacking physics, a danger line, chain scoring, a next-creature preview, saved best score, sound effects with mute, and drag-to-aim controls made for phones. Works on mobile and desktop. Easy settings at the top of the code.