Dezaemon is the first in the series, released on 1991 on the Famicom by Athena.
Just like the rest of the Dezaemon series, this one allows the user to create their own shmup by using the tools within the game to create music, sprites, enemies and their patterns, and possibly powerups and their distribution rates.
Also like every game in the series, it comes with a sample game designed to show off the potential of the creation system. In this shmup, there are four stages which gets progressively more difficult. The powerups gotten from item carriers is random in that a different powerup will appear with subsequent plays.
The weapons can be powered up by collecting the same type constantly and change if a new type is collected. They are a standard vulcan shot that gets bigger when powered up, a pulse laser that increases it's attack area (looking like a max level Main Shot from TGL) as it's powered up, missiles that explode in a spread blast that increases as powered up, pods that max out at 3, and shields.