I like it. Good game.
Good: Quick to pick up and play. Strategies (do you upgrade your firepower for easier kills or your time limit for longer life span?). Switching colors ala Ikaruga.
Bad: When hit, very easy to miss that your time got reduced by 10 seconds. Maybe a better 'notification' you got hit maybe? Maybe also being able to pick which gun type to upgrade rather than seemingly random choice of what side they'll shoot at.
Other: All in all, great game. I like it. Good for a quick shooting game. I even got into the top 10% on my first go at it. ^_^