Image from Danny Choo.com.
Gundam Unicorn in my opinion, is one unique Gundam. So far, it only appears in novel, but being a Katoki design made it extremely hot in among Gundam fans. In its normal mode, Gundam Unicorn's trademark is the huge horn on its head, very much like the horn of a Unicorn. Also, it's painted completely in white, no doubt to push it much closer to resemble the mystical creature. The paint exterior armor is actually Psychoframe, the same material used for the cockpit system of Nu Gundam and Sazabi, which enhance the MS's response to the pilot's will. A full Psychoframe Gundam is of course, the pinnacle of such psychic technology during the Universal Century.
Image from Mahq.net.
However, Gundam Unicorn's real secret is its Destroy mode, which heighten the Gundam's sensor against its environment for more accurate reflex in both its defense and offense. Like the Phase Shift armor seen on SEED and SEED Destiny Gundams, the effect of the Destroy mode (or 'God' mode I would call it :) is limited to a very short period of time. In Destroy mode, the armors on various parts of the Gundam are lifted, revealing some shining inner mechanism, which is plain awesome! Read more about it on Mahq.net.
If size is a matter to consider for purchasing a particular Gunpla for you, then Gundam Unicorn (head height 21.7 meter in normal mode, and 19.7 meter in Destroy mode), especially a MG version is definitely something to look forward to.
