It was pretty good! I was getting a little bored rolling around around mass 8 being so much bigger, but when I actually found a bigger ball and it started chasing me I was once again entertained until it ate me.

Liked the idea that you can spend your size to move faster.

It needs to be faster!
Check out this:
http://www.ludumdare.com/compo/ludum-dare-24/?action=preview&uid=14039

I liked that you absorbed the colour and not only the mass.

Seconding the "it needs to be faster."

I got to mass 3 and appeared to run out of things to absorb. Are more AI balls randomly generated?

I guess I just beat the game =P (mass=1427.812)

A bit slow to start and the movement feels a bit to slow. However I like the idea and found it entertaining.

I like the game!
Overall it's well done, the idea is not used a thousand times, it's fun and looks not bad.
Small things like the changing color of the ball are what differentiate good games from really good games.
Not that good:
The graphics: Huge balls are clearly polygons (don't know if it's your "fault" or done by unity), and the background ends at some point, there is just blue color. Instead you could draw your background as often as needed (depending on the camera position).
And gameplay: The bigger the ball, the slower it seems to be. At the end I was eaten by a ball far bigger than mine (I had 112 mass), and both balls could not really move, but it grew more than I, so it ate me. Higher velocity with higher mass would be nice, since it's not really much to play at the end.
But I really like the idea, it's fun to play and looks good!

Sound would help and the game is a bit slow, but congrats on your first Ludum Dare... well done!

I found that there was always stuff to suck up or stuff to suck you up, and the game ended after I hit 149.9821 mass and another ball hit a mass so huge that it took up the entire screen. Overall, interesting idea, but I felt it was reminiscent of the game 'Osmos.'