Look at the second image. If you can get 4 yellow dots to form a square, that will knock out all the yellow squares on the board.
The object of the game is to solve the 130 levels. Each level will have a slightly different objective. For example, you may be given 20 moves to somehow eliminate 15 yellow dots and 15 red dots. The key strategy, almost always, is to get those square chains, which can be difficult.
At the moment, I'm on level 105 or thereabouts.
Is there a Candy Crush element to TwoDots? Yes, but because there is a lot of randomness and invitations to purchase more lives.
When I run out of lives on TwoDots, I switch to Folt, until I run out of lives on that game.
Both games have a much better than Candy Crush.
TwoDots is fun!