Stacking games come in two kinds. In one, a block slides back and forth and you tap to drop it on the stack; whatever hangs over the edge is cut off. In the other, a block swings from a crane and you let go at the right moment. Arena13 has one of each: Stack Up and Sky Tower. Here is how each one really works, and how to build higher.
Stack Up: the sliding block
- Each new block slides in from alternating sides and bounces between the edges. Tap, click, or press Space to drop it.
- Only the part that lands on the block below stays. The overhang is cut off and falls, so the stack gets narrower with every miss.
- Miss the stack completely and the block falls: game over.
- A perfect drop lands almost exactly on top of the block below. You keep the full width, and the screen flashes "Perfect". From the third perfect in a row, each perfect grows your block back a little, never wider than it started.
- The blocks speed up as you climb, up to a limit. Your score is your height.
Sky Tower: the swinging crane
- A block swings from a crane. Tap or press Space to let it go.
- Blocks are never cut. If one lands too far off the floor below, it misses; if it hangs over the edge, it tips over. Either way you lose one of your three hearts, and the third loss ends the game.
- Every landing scores 25 points plus 25 for each perfect landing in your current streak. A perfect landing is one close to the centre of the block below. Any landing that is not perfect resets the streak.
- From floor 5 the tower starts to sway, and at 10, 20 and 30 floors the crane swings faster and wider.
Tips for both
- Watch the edge, not the block. In Stack Up, fix your eye on the edge of the stack the block is sliding toward and tap as the edges line up. Following the moving block makes you late.
- Find the rhythm. At a given speed a block takes the same time to cross every time. Count it once or twice and tap on the beat.
- Chase perfects early. In Stack Up, perfects only start growing your block back once you have three in a row. Streaks are easiest while the blocks are still slow, so get them early.
- In Sky Tower, watch a few swings first. The swing has a steady rhythm. Before your first drop, watch where the block passes over the tower, then let go at that same point in the swing each time.
- Mind the sway. Once the tower sways, aim for where the top of the tower will be when the block lands, not where it is now.
- Do not panic after a miss. In Stack Up a narrow block is harder but not hopeless; slow down and aim for perfects to grow it back. In Sky Tower one lost heart still leaves two.
Challenge a friend
Both games keep a score, so after a run you can send a battle link from the game-over panel. Your friend sees the height to beat, and they win the battle if they build higher.
How it was made
I wrote this with help from Claude, an AI assistant, and checked every rule against the games' code. If you have a stacking trick that beats these, tell me.
