Just read the descrition:

- "Reach the target numbers with as few moves as possible" is this a platformer, where I must travel to the numbers or, being numbers, I have to do a series of operations to get to the target?

- "the bubbles pile up to the top of the screen" There are bubbles? What do they do? do they hinder me in any way (besides making me lose)? "...reach the top" Am I going to be climbing?

From the text alone, I have no idea of the game. You failed to establish context - what I will be doing and how - and only talked about the goal (and that was vague), and the losing condition.

Now lets look at the pictures:

Ok, now I see the bubbles, the top, and the main idea of the game. You have a "tower" of numbers that is growing, and you will be berforming arithmetic operations with them to reach the target.

I didn't get exacly the steps to work with the numbers. I suspect is: 1- touch a number (8), 2- Touch an operation (-), 3- touch another number (5). You get 8-5=3, so I imagine you get a "3" bubble. I also assume you can only use two adjacent numbers (or where would the new bubble appear?).

If you get the target you get points. You can also swipe a number to remove it from the tower, with a penalty.

In conclusion, it could be better. I am assuming a lot from the pictures, so they should be clearer. Show the steps I have to take to works with the numbers. The textual description says nothing about the game. Describe the game in brief sentences: "You tower of numbers is growing without end! Do mathematical operations with them to prevent it from growing too much. Everytime you get the target number, you get points." Or something like it.

Looks interesting, but I don't have an iPhone so can't give you a full review. From the description though I think I understand, what confused me a little more (I haven't had my coffee yet so it may just be me :) ) is the screenshots. The first shot shows an 8 about 4 or 5 numbers down and an 8 at the top. The one further down is green but in the next shot the one further up is green. The next shot shows a 3 (I understand how you got there) but then the next shot shows the 5. It seems like they are out of order in the screenshots. The swipe more to earn more points is unclear to me as well.

This may be an iPhone thing, but why even have the swipe? Why not just do the math and as the math is done correctly the bubbles disappear.

I like the concept though and it seems like it would be a really good game for learning/practicing math skills while also keeping your brain fresh.