Every move repaints the block in the top left corner. Anything touching it in that colour joins the block, and the board slowly becomes one colour.
Pick your grid size and how many colours you want, and see whether you can finish inside the move allowance.
The block in the top left corner is yours, even when it is only one square. Choose a colour from the row under the board and your whole block turns that colour.
Any cell of that colour touching your block joins it, and so does anything touching those, so one well chosen colour can swallow a large area at once.
Each choice costs a move. The counter under the board shows how many you have used against the allowance for that size.
Running out does not stop the game. You can keep going and finish the board, it just will not count as a clean win.
Turn the whole board one colour within the move allowance. The block always grows from the top left corner.
Usually, but not always. Late on, the colour that reaches a large untouched region two moves away beats the one that grabs a few cells now.
Nothing stops. The counter keeps going so you can always finish the board, and New Game deals a fresh one whenever you want.
Yes. The dropdowns above the grid set the size and the number of colours, and either one deals a new board straight away.
Flood It is a colour flooding puzzle that has been rebuilt countless times since the original browser version, and the appeal is the same every time: the rules take a sentence and the decisions take a while.
Greedy play gets you most of the way. The interesting part is the last few moves, where the board splits into pockets and the order you take them in decides whether you finish on time.
Fewer colours makes a board easier, more colours makes it longer, and a bigger grid mostly makes it slower rather than harder.