The full name of the opening is Réti Opening: Dutch, Lisitsyn, Rydel-Bloodgood, Polish Gambit, Dalesio Gambit. Don’t worry, you don’t have to remember that. Just keep in mind the initial moves:
1. ♘f3 f5 2. e4 fxe4 3. ♘g5
The opening slightly resembles the Tennison Gambit, as White makes a similar early knight charge to provoke Black to weaken their king’s defenses. This time, we won’t just win the opponent’s queen, but deliver a nice checkmate in the center. I will explain all the details in the game comments: