I got it and am enjoying it quite a bit. I'd say it's almost as fun as Deathsmiles, but offers a different experience. Has quite a bit of content for a $10 game. Just make sure you switch the voices to Japanese.
As for strategies, the one that's worked for me so far :
Alternate between the barrier and spell cards. Activate barrier first, once it runs out use a spell card, activate barrier again the moment a spell card runs out, repeat. Just make sure to visit the shops often to keep your supply of spell cards full. Also make sure to buy MP bottles whenever they're available. I recommend picking a character with a high barrier rating. And make sure to let go of the fire button every few seconds when you're not using a spell card, you can suck up all of the coins on the screen that way, otherwise they'll drop off. You can keep the fire button held down during spell card mode though.