I built Pivot & Merge, a puzzle game with no timer. It started because my kid asked for a game while we were out and my phone had exactly zero. What I borrowed from Tetris, Puyo Puyo and 2048, and what I deliberately left out.
When we're out somewhere, my kid will ask to play a game. Usually when a wait suddenly gets a lot longer than anyone planned for.
So I check my phone and there is nothing on it. Not because I don't like games. I don't have time for them, and if one is installed I will absolutely end up poking at it, so I stopped installing them at all. Glad it's not just us, if anyone else does this.
What I settled before writing any code wasn't features. It was constraints. Less a spec, more a list of things not to do.
That third one matters more than it sounds. Hand a kid a game with no ending and you become the guy whose job is saying "okay, that's enough now." I wanted out of that job.
Tetris, Puyo Puyo, 2048, HATETRIS, Reversi (Othello).
Tetris, the shapes and the rules are just absurdly refined. I watched the Tetris movie too, and yeah, I get why the world lost it over this thing. Then Puyo Puyo came out of that.
I figured simple games were done being invented, and then 2048 showed up. It's downstream of Threes! and 1024, sure, everybody knows that. Still, a genuinely new game, in this era? That got me.
HATETRIS is the same kind of surprise. Change one rule, the piece that drops is always the worst possible one, and it's a different game entirely. One line of spec, and it moves that much.
What I actually wanted was the Reversi (Othello) idea.
A minute to learn, a lifetime to master
Touch it for a bit and you know the rules. A kid knows the rules. Something I can hand a kid that's also a little bit of practice. That was the thing I wanted to build.
What I did, mostly, was cherry-pick.
2048 is turn-based but nothing chains. Puyo Puyo chains but the pieces fall on their own clock. I pulled those two apart and took one half of each.
Put a finger on the board and the nearest 2×2 rotates. Matching numbers merge, tiles drop into the gap that leaves, and if they line up again down there, that's a chain.
It's turn-based, so nothing moves until you touch it. If someone calls you, you close it right there, and the board is still sitting where you left it next time.
My kid worked out that four in a square makes 8, and started building that shape on purpose. Feels like the doubling lands before the addition does. Somewhere in my head a quiet huh, you got there faster than I did went off. If you've got powers of two in your hands, that's maybe half the times tables already?
"Kids pick up number sense naturally" would be overselling it.
Easy to start, easy to put down, fine to hand to a kid. That's about all I was going for. Whether it takes a lifetime to master I genuinely don't know yet. My own best tile is stuck at 16384...