Dr. Toppel's Adventure is a straight-forward vertical cute-'em-up with goofy enemies, colorful backgrounds, challenging gameplay and one main powering-up method.
You have two buttons to go along with the joystick, fire and pod-locking. As you go thru the game, some of the enemies you kill turn into power-ups in the form of additional pods that get attached to your ship and add to the firepower. Actually, your character looks like some sort of amphibian and the pods that get added look like little baby versions of yourself. Anyway, you can continue to add to your pods (I've seen at least 5 attached) and they start as a line in front of you (protecting you and firing). But, like other shooters, as you move around, your pods rotate around you in a connected, chain-like sort of way and can wind up firing in any direction. Then as you continue to move, they continue to move around you and fire relative to how you move. HOWEVER, the good news is that if you like a particular configuration, you can push the 2nd button and lock the pods in that formation. So, when you move, the pods stay in that exact formation and fire the same direction regardless of where you go. Conversely, if you want to change it up, simply push the 2nd button again and the pods are unlocked, moving and rotating around you like before (but still attached). So, the 2nd button is a toggle switch to lock/unlock your helpers.
The pods/helpers stay until they are picked off (individually). So, you may lose one here or there, but you get to keep the rest if they haven't fallen victim to enemy fire. The way they move is precise and subtle, so there are gazillions of combinations to figure out how to maximize your firepower. It takes some skillful back and forth and locking and unlocking to get them all to fire forward in a side-by-side, wide sort of way (as opposed to single file straight ahead).
Of course, there are other bonuses to be gobbled and there are coolio level bosses to contend with, but mostly the game is about arranging your offense, shooting everything in sight and the psychedelic color scheme.