Dangerous Seed (デンジャラスシー) is a vertical scrolling shooter arcade game developed by Namco and Tose in 1989 for Japan only; it runs on Namco System 1 hardware and was later given a port to the Sega Mega Drive in Japan a year later in 1990. The game was the first from the company to include a year at the bottom of the "legal notice", which was typical for many of the company's earlier 16-bit arcade games.
The player starts off with three fighters, Alpha, Beta and Delta. The player must complete four stages by using each ship individually, with the latter all having their own amount of hit points. If Alpha gets destroyed, the Beta will appear in its place; and if Beta should get destroyed then Delta will appear in its place, and finally if Delta shall get destroyed then the game will be over. If the player survives the four stages, then all three craft will combine together into "Moon Diver" that features a large amount of firepower.
The player can destroy enemies known as "Turtles" to acquire a special weapon that can be used whenever the player chooses:
- Ring-Laser (Alpha)
- Melt-Missiles (Beta)
- Hyper-Bombs (Delta)
- Energy-Capsule (any)
- Hyper-Booster (any)
The Energy Capsule will refill the player's hit meter to full, while the Hyper Booster will warp the player to the end stage boss.