Lightning Fighters
Lightning Fighters, released in Japan as Trigon, is a 1990 scrolling shooter arcade game by Konami. It is commonly compared to Raiden, though the two games were released very close to each other, and they were both meant to compete with the works of Toaplan.
Though Lightning Fighters has become an obscure arcade-only title, Konami has referenced it multiple times over the years. Gradius Gaiden features a boss modeled after the ship and weapons from the game, and Yu-Gi-Oh! cards such as "Trigon", "Delta Tri" (based on the mentioned Gradius Gaiden boss), and "Dragon Laser" also represent the game.