Collatz Hailstone Link vs Gem Falls

Collatz Hailstone Link — a relaxing number-merge puzzle built on one of math's most famous mysteries: the Collatz conjecture (the "3n+1" problem). Drag and merge numbered tiles, watch each sum bounce through the hailstone sequence, and chase the highest — or lowest — final number you can reach. Easy to learn in seconds, deep enough to keep you coming back for a better score. HOW TO PLAY • Drag one tile onto another (or tap one, then another) to merge them. • The two values are added, then the Collatz rule is applied to the sum: - Even sum → divide by 2 (the tile turns blue) - Odd sum → multiply by 3 and add 1 (the tile turns orange) • Chain the same color in a row to build a streak bonus. • Keep merging until a single tile remains. Push that last value as high — or as low — as you can! FEATURES • Pure one-finger gameplay — merge with a drag or a tap. • 7 board shapes: Square, Hexagon, Triangle, and four hybrid layouts. • Three-part scoring: turn points, streak bonuses, and a final bonus based on your last number. • Undo your recent moves to plan the perfect chain. • Records screen — sort your runs by score, max value, final value, and date. • Global online leaderboards — compete on both High Score and Final Max. • Light & Dark themes. • English & Korean language support. • Play offline, anywhere — no account required. WHY YOU'LL LOVE IT A quick puzzle for a coffee break, a brain teaser for math lovers, and a satisfying score-chaser for everyone in between. Every board is a fresh little puzzle in number theory — no two runs feel the same. Merge the numbers. Ride the hailstones. Beat your best.

Match three or more, watch the cascade take the rest, and keep going. Gemfall is an endless match-3 built for picking up and putting down. Every level asks for something different. Clear a colour, break through the ice, bring the cargo home. And when you close the app mid-run, the board, the score and your powerups are waiting exactly as you left them. No timer running against your day, no lives to wait for, no move you have to make right now. FOURTEEN WORLDS Every level is set somewhere, and where never changes: level two is a Maya temple in the jungle, level four is a dead valley under an erupting volcano, and they will be next time too. A wreck on the sea floor. A sweet factory. A frozen kingdom, a haunted mansion, a marble gate in the clouds, a garden at sunset, a gorge full of waterfalls, a toy box at the end of the afternoon, a fjord under the northern lights. Each world has its own six pieces, its own board, and its own weather in the air above it. CLASSIC Endless levels, each with its own objective. Chain your matches to build heat, and every gem on the board is worth more while it lasts. Clear the level, fall through the warp, and the next one asks a little more of you. TIME ATTACK Sixty seconds. Every match buys you a few more. See how far you can stretch the clock. POWER GEMS Four in a row makes a gem that clears a whole line. An L or a T makes one that blows a hole in the board. Five in a row makes the star. The rarest piece in the game and worth waiting for. Put two power gems together and the board comes apart. ICE, STONE AND CARGO Later levels do not just hand you the board. Ice freezes gems in place until you break the shell. Stone blocks take repeated knocks. Cargo has to be walked all the way to the bottom before it counts. FAIR BY DESIGN · Free. No in-app purchases, no subscriptions, no ads. Nothing is locked behind a paywall, because there is no paywall. · Fully playable offline. · Nothing is collected. No analytics, no tracking, no account, no sign-up. Your run lives on your phone and nowhere else. · The six gems differ in shape as well as in colour, so they stay apart if you do not see colour the way most people do. GAME CENTER Sign in to Game Center and your best Classic and Time Attack scores go on Apple's global leaderboards. Skip it and the game plays exactly the same, minus a rank. Gemfall is built from scratch in Swift for iPhone, rebuilt from the browser game of the same name. iPhone, portrait, iOS 18 or later.