I'm currently making two completely different types of shmups (2d shooters if you do not know) but I don't want to have the basic gun and bomb powerup. Other than bullets and really long laser beams, what other powerup can be in a shmup shooter?
Definitely homing missiles is always a must for power-ups, but a much higher rate of fire and larger bullet spread are common too. S homing missile variant that charges a laser for a couple seconds while targeting nearby opponents, then destroying them all in simultaneous individual laser blasts could be possible. It'd work like a bomb, but look really cool in the process. I'd definitely buy it if that was in it, I know that. If you decide to use elemental power-ups, a homing continuous-damage electrical attack like the one in "Dragon Force Light" is good, and as the previously mentioned flamethrower.
Definitely Shields, maybe magnets if you are using coins and such as means of upgrading. Weapon spread was a good idea, especially doubling the amounts of bullets.
Maybe I'll also add a laser bar that moves through the level and kills all in it's path, like lov grav racer 2.
