I'm tempted to just stop there and proclaim the game a complete failure by screwing up its main concept. But PowerUp Forever is a cool-looking take on the genre that survives even when faced with the non-foreverness of its powerupitude. It's like someone sat down with Flow or the first stage of Spore and said "what if we made this an actual game?" So you're sort of traversing a smooth, liquid world where your movement and attacks swirl the colored liquid about, producing something trippy, but also something much more relaxed than, say, the color-cycling, candy-flipping shader madness of something like Space Giraffe. Against that background you'll find a number of different enemies, like circular drones, big worms that shoot bullets out of their sides, and other vaguely organic-looking creatures. The most important enemy creatures are the parasites--little space neon squids that are your primary target. By destroying enough of these parasites as they flutter around and grab onto larger enemies, you'll summon a guardian. The guardians look more like ships than creatures, much like your own craft. You'll engage them in a bullet-filled circle strafe to the death, and when you win, you'll get a power-up and grow larger. Then the cycle begins anew and you're back on the hunt for parasites.
The way you grow every time you beat a guardian gives the game an evolution-themed feel to it. Large, dormant enemies that used to ignore you and serve as fuel tanks for parasites spring to life and begin fighting. Meanwhile, the old enemies get smaller and smaller until you can just run into them without taking damage. The game uses a Halo-style recharging shield, but if you get hit once while your shields are out, it's game over.
The upgrades in PowerUp Forever are automatic. You'll get a manual shield that can be used to absorb or reflect bullets. Your default cannon will get a wider spread, and you'll also get two more weapons. There's a laser targeting device that shoots homing missiles when it locks and a plasma weapon that's essentially a Star Trek-style photon torpedo. I typically stuck with the default weapon and did just fine. As you blast enemies, you refill your secondary weapon gauge, which is used for the plasma, the laser, and a screen-clearing smart bomb. Saving up for the smart bomb and dropping it at the beginning of a guardian fight gives you the upper hand right away and seemed like the best way to handle business. But you eventually reach a maximum level of upgrade for all of your weapons. Once you've gotten all of the "real" power-ups, you just start getting an extra meter full of bonus energy as an "overcharge." If that meter is already full when you kill a guardian, you get nothing. No power-ups.
OK, I'll stop harping on the name. It's not that big of a deal. PowerUp Forever is a pretty good dual-joystick shooter that stands out, even though there are now around a billion of these games available on various digital download services. If you felt that Flow was too soft, or that you wanted more guns in the first stage of Spore, you'll certainly dig it.