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 more cautious with respect to king safety. 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
Black is lost because the White knights cannot be stopped. The knight on d4 threatens check which can only be avoided by moving the king to e8, but then the knight on b5 can deliver check on c7.