Stack

A coloured slab slides across the screen and you tap to drop it on the tower below. Miss the alignment and the overhang shears off, so the next slab is narrower, and the one after that narrower still.

One tap, one slab, nothing else

That is the entire game, and Ketchapp has never pretended otherwise. Nothing needs explaining and a first-time player is competent inside ten seconds. The loop is tense for a while, because every imprecise tap shrinks the target, so mistakes compound rather than reset and a tower that started forgiving ends up demanding taps against a sliver. The gradient shifts colour as the stack climbs, which is the only sense of progress on offer, and the click on a clean drop is satisfying enough to carry you a few rounds past the point you meant to stop.

Execution you can admire

The visual language is clean, the audio lands exactly on the drop rather than a fraction behind it, and the whole thing runs without stutter on hardware that struggles with much else. No tutorial, no account, no opening cinematic. For the specific job of being instantly playable on any phone, this is close to the most competent version of the formula.

Where the tower stops being interesting

Once your thumb has internalised the timing, the only variable left is how long you can hold concentration, and that is not a game, it is a test. Nothing waits behind the mechanic to change the question: no modes, no unlockables, no reason to chase a score beyond your own last one. The interstitials between runs make it worse in a specific way, because being instant is the one thing this app is good at, and a full-screen advert between two short attempts removes exactly that.

As a minute of distraction it does the job cleanly, and as anything more it evaporates almost immediately. The slab-dropping rhythm is worth trying once, if only to see how precisely a single mechanic can be tuned. Keep it for a couple of days and expect nothing past that.