How BrainDrop Games Work

Last reviewed: 8 September 2026

⚡ Short version: Every puzzle is generated in your browser by our own code. Nothing you play is sent anywhere. Here is exactly how each game builds a puzzle, and what we do and don't claim about it.

Where the puzzles come from

Sudoku starts from a completed grid built by a backtracking solver, then removes cells while checking that exactly one solution remains. That uniqueness check is what separates a real sudoku from a grid of numbers — a puzzle with two solutions is a bug, and we treat it as one.

Word search places each target word in a grid at one of eight orientations, retrying on collision, then fills the remainder with random letters. Every listed word is guaranteed placed before the grid is shown.

Crossword builds a grid from an intersecting word set and pairs each entry with its clue. Wordle-style play draws the answer from a curated list of common English words and validates guesses against a larger accepted-word list — the same two-list structure the format has used since the original.

Maze generation is a randomised depth-first carve, which guarantees exactly one path between any two cells. Memory and speed shuffle and time in the browser with no server involvement. Jigsaw slices an image into pieces client-side.

Trivia draws from a question bank across eight topics at three difficulty levels. Questions and answers are checked before they go in, but a bank this size will contain mistakes, and some answers go out of date. If you find one that is wrong, tell us which question — we will correct it. We would rather be told than be quietly wrong.

Difficulty, honestly

Difficulty labels describe the puzzle, not you. In sudoku it is roughly how many cells are removed and which solving techniques are needed; in trivia it is how obscure the subject matter is. These are our judgements, not a calibrated scale, and they are not comparable to any other site's labels.

What we don't do

No accounts, ever. There is nothing to sign up for. Streaks and high scores live in your browser's local storage, on your device. Clear your browser data and they are gone — we cannot restore them, because we never had them.

No health claims. We do not claim these games prevent cognitive decline or improve memory in everyday life. Training a specific task improves that task; broad transfer to daily function is not well supported by the evidence, and regulators have acted against companies that said otherwise. We build these because they are enjoyable.

No dark patterns. No forced ad view before a game, no fake countdowns, no "one life left" upsell. Ads sit around the game, not in front of it.

Accessibility

Games are built to work with keyboard input where the format allows, at a range of screen sizes, and without requiring fast reflexes — except the speed trainer, which is about reaction time by definition. The seniors section About How It Works raises type size and contrast further. If a game is unusable for you in a specific way, that is a bug worth reporting.

Corrections

Report a wrong answer, an unsolvable puzzle or a broken game through the contact page, naming the game and, for trivia, the question. We fix it and note significant corrections here.

Corrections log