Casual and shooter aren't two words that go together often, but that doesn't mean it's not possible.  Void Invaders is a retro-styled arcade using Space Invaders-inspired art, screen-filling colorful explosions and a forgiving nature.  Enemies pop in and run through their patterns, sometimes attacking and others aiming right for you, and you get to clear them away so the next wave has a chance to mow you down.  It's a simple and easy little shooter, but likable and enjoyably frenetic all the same.

Each of the twenty levels of Void Invaders is comprised of a set pattern of enemies, arriving in a series of waves throughout each level.  At first the aliens simply wander back and forth across the screen, but it doesn't take long before they're dropping bombs or shooting out sprays of bullet-absorbing firepower.  The ship's main gun shoots in a scattershot style, making for a nice cone of fire that rewards pray & spray shooting over precise targeting.  Power-ups appear at predetermined points in each level, providing a good variety of fun new guns to play with, and the variations in weaponry are spread out so that when one gets old, another is showing up soon.  Admitted, there's only five of them total (triple, quintuple, rotating, and wave shotguns, tornado, and a special one-off gun called Insanity that, technically, makes six, but you never see it again so I'm not counting it) but Void Invaders is fairly short it works out fine.

While the level progression and enemy patterns are fun and varied, the actual game itself is easily beaten in a single sitting.  Unlockable difficulties help extend things a bit but I still cleared even the ominously-named Nightmare mode in under two hours from first firing up the game.  A big contributor to the easiness is the level-up system, which is a bit generous with its rewards.  Kill aliens to get faster, do more damage, and increase the rate of fire is always nice, but in a simple progression of playing all twenty levels on Normal, then Hard, then Nightmare, I actually found Nightmare to be quicker and easier than Normal.  The enemies were faster and more aggressive, sure, but they went down much faster thanks to a combination of experience with the level patterns and being far stronger than they seem designed for.  Seeing as Hard doesn't open until Normal is beaten, and Nightmare until Hard is cleared, that means you can't play on an appropriate difficulty level until you're both strong and experienced enough to blow past it.

Closing Comments:

What this ends up meaning is that Void Invaders is a casual shooter, something to blast through when in the mood for a light show instead of a challenge.  It's a nice light show, with giant pixel-monsters streaming into the stage and exploding everywhere, but its simplicity makes it more a snack-sized bite of shooting action rather than anything you can sink your teeth into.  An endless mode tries to inject a little longevity into the game but its random selection of critters is far less interesting than the hand-built patterns of the main game.  Void Invaders is a fun little snack of a shooter, quick and pleasant and sugary, but you'll be hungry for more than it has to offer fairly quickly.