The overall feeling one gets from No Gravity is laced with modesty. Its a simple game, one where its homebrew roots are clearly evident. Its production values may not be as high as the Triple-A, big-name studio titles, but it does do a pretty good job at putting out a worthy shooter. The game may lack FMVs and the story is told through stills, but the controls are smooth and easy to pick up.
The first mission is a tutorial stage, where the objective is to blow up a bunch of asteroids before they hit the player's flagship. After getting acquainted with the controls (use the analog stick to maneuver, x button for gunfire) and tactical skills (example: tap shoulder buttons twice to dodge roll) it'll be time to test combat prowess against live enemies. However, there is one thing the tutorial forgot to mention: how to read the HUD. That's a pretty important thing to miss, seeing as there are four bars on the HUD which don't clearly indicate what they represent. As far as I could figure out, the one marked by an infinity sign is for gunfire power ups; the one with a symbol of a circle surrounded by four lines is ship health.
Each mission has multiple objectives. So, the first part of a mission might be to blow up the enemy's minefield before your team can proceed to go on an all-out attack; the latter half might be a battle with an enemy flagship. This approach to mission structure adds a layer of personality and excitement to each outing, as you're not really sure what would happen next. Say you clear the minefield and destroy the flagship -- you may think that it's over, but then there's a surprise attack from another squadron of enemy fighters.
One glaring nuisance is the absence of voice-overs during combat missions. The player-controlled pilot is part of a squadron of space fighters, but the lack of vocal communication between these crafts leaves the player with the feeling of being alone. It's too quiet; you'll soon feel that void, that emptiness of space ... plaguing your mind. Simple lines like "Nice Shot!" or "I'm hit" could help break the silence and at least give the illusion that there are pilots in those other fighters. The game's electronica soundtrack will be filling your ears during missions; however, while fitting and entertaining, it can get stale quickly without the voice-overs to add in some texture.
The graphics are average for a PSP game, a bit rough on the edges in some spots, yet very detailed in other areas. Environmental objects look rather bland, though the spacecrafts you can pilot and enemy ships look great. The visual effects are stellar, though rarely used. While in cockpit camera view (there are two views: cockpit and third-person) player's can see cracks appear on their windshields as they take damage.
One nice feature is that player's can swap characters between missions. Each character is assigned a particular ship with unique stats (four stat ratings: fire, missile, speed, shield), so choosing the right fighter for a particular mission is embedded in the strategy. This set-up, however, basically means characters are not fleshed out and don't have unique storylines -- they all share the same path. The game starts off with three pilots/ships but will grow to include two more.
No Gravity is a simple, yet fun little distraction. It's mission-based gameplay seems tailored for quick on-the-go gaming. If you're looking for something to play on the ride to work or on some other trip, it might be worth looking at. If you're in need of something that's really deep and engaging, you might want to look elsewhere. No Gravity takes up very little space on a memory stick at only 49MB, and only costs $10.