First check chess is a simple version of chess in which you win by giving check i.e. attacking your opponent’s king. It does not need to be checkmate. It does not matter if the checking piece is immediately captured.
Black is lost because there are two check threats (Qxf7+ and Qxe5+) and only one can be stopped.
Compared to orthodox chess, it is necessary to be very defensive with respect to king safety especially for the second player. Games are short because defence is difficult. Learning from the above game, Black should try another move if White opens 1.e4. In the next game, Black responds with 1..e6
The game can be extended by requiring that two or three checks are required in order to win.