Is this game good enough to succeed in AppStore?

It's polished, but the game does not have marketable unique features. i.e. it would only see success if the market were to go through a very long period where no or few new matching games are released.

Right now that market is congested with titles, and to break through the noise you would have to substantially raise scope and provide more content and IP(story, characters, elaborate level design, etc.) or more features(multiplayer, level editor, additional game dynamics like the RPG elements of Puzzle Quest et al.)

If you want to break through without raising scope, look for a niche that hasn't been well-covered, and prototype it a few times until you hit on one with a good dynamic.

For example, matching plus tower defense. Will it work? The examples I've seen are few and do it in the crudest way(minigame + minigame - never a recipe for success). Find a way to change their mechanics so that they integrate better, and you might strike gold. Even if you fail, you'll still accumulate design ideas that can be fed into the next game.

Yep, the polish of the mechanics is there.

Maybe try to put something more significant inside the blocks, like a sci-fi theme (birds and pigs are popular too I hear :)

Fun to play.

I actually played it for a while and it's actually kind of addicting.

No one here will be able to tell you whether or not something will definitely succeed or not. The best way to find out is to try. Anyone that claims otherwise is full of it.