When zergling attack a colossus, or a base - wouldn't it be great if they could climb onto the structure (or up the unit's legs) and attack instead of surrounding it only. It would look great with zerglings swarming on top of a base. What other attack type graphics would you like to see? Perhaps a mthod of throwing/catapulting zerglings onto a carrier to attack it - or possibly onto a battlecruiser... very far out, but an idea... This would add to the realism (well the first suggestion anyway).
No. Things like this would interfere with what's important; the competitive gameplay. Anything goes, though, in the single-player.
How would it effect the competitive gameplay? If anything, it would make the game look more realistic and way cooler. If zerglings can climb onto buildings it would really look awesome - imagine 50 zergling swarming all over a terran base, tearing into the steel structure.
What if you need to recall those Zerglings? They would have to jump off so quickly that it would destroy any realism it was implemented to achieve anyways. Besides, if you're looking at the Zerglings you aren't playing StarCraft right.
Not even in singleplayer. It wakes no sense. Even a Zergling would know that attacking the legis is more effective then attacking the rest. Also, attacking a building from the top? Why would you not want to attack the foundations? Still, it would look awesome in cinematics. But my guess is that Blizzard already thought of that.
As others have said, I don't think having units on top of a building would be good because it does affect gameplay. However, there should definitely be various attack patterns (different types of slashing for melee units, maybe changing positions or something for ranged units) just to make things feel a bit more fresh and realistic, in a way that does NOT affect gameplay in any way.
In summation, there are certain games that are meant to be nice to watch and there are games meant to be nice to compete. Games like Dawn Of War are nice to watch because they had more complex animations but that doesn't really work in a competitive environment. StarCraft is a competitive game where useless gameplay-altering animations should be kept to a strict minimum. Just because other games do it doesn't mean StarCraft should.
One last comment from me on this: units and buildings are scaled up and down to make it fit on your screen. How weird would it look to have an entire Collosus covered by 3 Zerglings or so... Just think back of that CGI of Mutalisks attacking a Carrier.
Don't worry about the cinematics. In every cinematic where we have seen Zerglings fighting (Brood War opening and the StarCraft Ghost cinematic) the Zerglings have jumped on their enemies instead of sitting in front of them.
Coold doesn't preclude balanced. Hopping on buildings might be overkill, but varied attack animations and cool moves would certainly spice up the game. If you want an example look a DoW2, attack animations are really good looking and inmersive, yet MP mode is highly competitive. SC2 being next-gen i expect bullets piercing, psi-blades slicing, and colossus melting things. Tetris minimalism would be a step backwards. Since actually superimposing a Zergling into a structure might cause balance issues I would vote that one down, but the general idea is good.
