I liked how interesting the card sounded at first and I think something like caring about the number of cards in the library should really be on a rare or a mythic. As for how fun it would be, I have no clue, I'd at least test this card at first.
In response to the playability of the card, I would recommend rechecking the math.
Its 0-1 damage for .
2-3 damage for .
and becomes a decent imitation of arrow storm at .
From there, it outpaces most fireballs and gets closer to Corrupt.
Also, the spell at this cost would rarely be good. So far it does:
0 damage for .
2 damage for .
4 damage for .
6 damage for .
8 damage for .
10 damage for .
12 damage for .
That cost to damage ratio might make for an arguably okay uncommon. But add to that the fact that you have to have a perfect number of cards in your deck to maximize the cost and damage... that makes the card only usable by people who enjoy being goofballs. Which, considering Link's point, might be appropriate...
I liked how interesting the card sounded at first and I think something like caring about the number of cards in the library should really be on a rare or a mythic. As for how fun it would be, I have no clue, I'd at least test this card at first.
In response to the playability of the card, I would recommend rechecking the math.
Its 0-1 damage for
.
2-3 damage for 
.
and becomes a decent imitation of arrow storm at 
.
From there, it outpaces most fireballs and gets closer to Corrupt.
Also, the spell at this cost would rarely be good. So far it does:
0 damage for
.
.
.
.
.
.
.
2 damage for
4 damage for
6 damage for
8 damage for
10 damage for
12 damage for
That cost to damage ratio might make for an arguably okay uncommon. But add to that the fact that you have to have a perfect number of cards in your deck to maximize the cost and damage... that makes the card only usable by people who enjoy being goofballs. Which, considering Link's point, might be appropriate...
It's a bit annoying to have to count your library. This would work very well online but it would be frustrating in paper.
Not sure this needs to target, as you're just grabbing stuff from exile.
Spatial*
This is more annoying evolving wilds in Limited and junk everywhere else.