I really like the concept of the game... but...
Overall, I do think it's really cool. But, I'm having a really hard time enjoying it. I know that might seem a bit confusing, but hear me out... or, I guess, keep reading... whatever.
First off, I almost never get a chance to actually look at the dudes I'm summoning. I'm too busy frantically trying to find matches to actually look at the action screen or whatever you want to call it to actually see if I'm winning or not. What little I've seen of the action looks awesome, and I want to be able to see my little dudes in action, but if I take the time to actually enjoy the action, I fall behind and lose! I have no idea how I'd improve on that, maybe have a "match to buy units" phase and a "deploy units phase" or something like that.
Second, buying more tiles is kind of counter-intuitive. See, it's hard enough finding matches quickly with just the 5 tiles, why would we want more? Especially a tile that does nothing but improve our score. It's like we're spending our money to make the game even harder, when there are already stages where the computer gets like 6 summons right off the bat and just PWNS us. Or rather it PWNS me, I can't speak for everybody. Maybe the shop could be upgrades to the units' special abilities? Like maybe if we buy "Fireball X" the mage can attack twice at once if we match a row of 4 mages? Or maybe buy the "fire golem" so we can auto-summon a giant fire monster if we set off a combo of 4 or more?
Third, this might just be me but I have a hell of a time telling the berserker and the warrior apart. I mean, we've got the GREEN archer, the YELLOW mage, the RED rogue, and then we've got the blue-gray berserker and the gray warrior. I know, one's a chick and one's a dude, I still have a lot of trouble telling them apart when I'm playing and it's cost me games. They look a lot alike. Maybe it's just me. I've even tried upgrading them to see if they'll look more different, and it didn't help.
Anyway, it's good but I think it could be better and I really hope that you make another version, one that's a little kinder to eternal (and possibly colorblind) n00bs like me.