We've already seen a few shoot 'em ups pop up on DSiWare, but for the most part the selection has felt more gimmicky than traditional. Flip the Core continues that tradition with a unique "flip" design that allows you to flip the flat background planes, greatly altering the level with one push of a button. And while this interesting gameplay twist does bring something new to the table, it sometimes holds the overall experience back more than it adds to it.
The basic gameplay revolves around manoeuvring your ship through the horizontal levels laid before you. Defeating enemies is as easy as firing your ship's cannon at them. As you defeat enemies, they'll release orbs that you can collect to add to your energy supply; the more energy you accumulate, the more powerful your cannon fire becomes. Of course merely firing the cannon consumes energy, so if you're looking to really power up, you'd better pick your targets carefully. If you completely fill up your energy, you will then begin to fill up your overcharge meter, used to unleash massively powerful firepower.
As if the enemies weren't enough of a hindrance, you'll also have to deal with the level itself, using the game's unique flip command to flip to a different plane in order to defeat some enemies and navigate around hazardous obstacles. But keep in mind, flipping an object in another plane directly into your ship won't work either and the game will automatically flip back to the previous plane if you attempt to do so.
The play controls are responsive enough to get by, but sometimes there's a certain looseness in the moving of your ship that can feel a tad slippery. The game does have an additional level select mode in addition to the main arcade game, but you'll have to unlock these levels in arcade mode before you can play them at random. It shouldn't be too much of a problem considering the game is fairly short in length.
The music and visuals in Flip the Core are both rather basic but at least the colourful abstract backdrops add a nice eye-catching look to the presentation. You won't see a lot in the way of detail, but there's certainly enough flare and variety to at least keep your attention on the game long enough to get through the various levels. Just don't expect an overwhelming desire to go back for seconds.
Hardcore shmup fans have been waiting a long time for a solid eShop title, but while Flip the Core features some nice gameplay ideas, the need to keep flipping planes and trying to keep track of levels that keep constantly changing ends up taking too much focus off of the core shooting experience. The inexpensive $2 price tag makes the game at least worth checking out for those who just can't get enough arcade shooting action, but that comes with the caveat of keeping your expectations in check when you do.