What?!
Zerglings are the fastest ground unit in the game and they can morph [anywhere] into those things that explode and dissolve armies in seconds. Not to mention you can amass a 100 strong Zergling force in negative 5 seconds. Hydralisks also seem to move faster than comparable units. Make them more mobile? You're joking.
I didn't mean mobile in terms of speed. I meant mobile in terms of movement options. Zerg have ground (move along ground, up and down ramps) and air (fly in a straight line from point A to point B). There is no Zerg units that can jump or step over cliffs.
Sure, zerglings are fast (especially with the movement speed upgrade), but there are so many units that gobble them for lunch that they're effectively useless (except as a burrowed unit for sight on expansions) after the first few minutes of the game in nearly all situations.
And maybe it's just my own experience or because I almost never get the movement speed upgrade, but I don't think hydralisks are that fast.
Sure, Zerg are fairly fast, but there's no real diversity in movement. It's like playing a chess game without any knights. Sure, you can still get your bishops and rooks across the board fast enough, but the game would lose a certain charm if you didn't have a unit with unconventional movement patterns. It's easy to predict where a player is going to take their bishop, rook, or pawn. It's much more difficult to predict where that knight is going to end up.
In short, it feels like Blizzard invested a lot of thought and effort in adding really cool new stuff to Terran and Protoss and Zerg was an afterthought. "Check this out! These Terran guys can jump cliffs and the dropships heal now. And Protoss can warp in units anywhere there's a pylon. How cool is that? Oh, right. That bug race. Yeh, we'll spruce up the nydus canal. Whatever. It's time for lunch."
The Colossus is also Tier 3 and warp gates (while very handy) only warp in units made at the warp gate.
Eh? Hitting W and then dropping a unit anywhere there's a pylon is pretty darn cool. If I played Protoss (and I've considered switching races), I'd probably be fond of building 4+ warp gates, building a 2-pylon, 2-cannon outpost, and warping in a zealot/sentry/stalker mix right outside the enemy base.
And how cool is the warp prism? A flying pylon? Oh man. It all seems so obvious: Void rays + deployed warp prism + 4 gateways + stalkers/zealots. It's like a medivac drop with viking support but at least 4 times as cool. Why don't we see more Warp Prisms in games?
Personally, I wish Protoss had a better Tier 1 unit... Zealot costs 100 minerals and only attacks ground units? It costs double what the Marine costs and does half the work! Granted, Protoss does have the stalker, but at 150 minerals and 50 gas, it isn't cheap compared to the competition.
Because zealots and stalkers are both sturdy units. In addition to their health, they have regenerating shields. They hit hard, they have auto-regen outside battle, and they have more HP. Of course they cost more.
The beginning of the game always seems to be the hardest time for me as Protoss. I usually never feel bad for Terrans when they get attacked early in game because they usually have about 100 marines and 5 marauders.
Now that we can agree on. Bioball (mass marines/marauders) does feel a bit too much like an "I Win" button right now. Maybe it's because the game is still new. Maybe it's because most of the viable Zerg counters involve ridiculous micro (banelings) or third-tier units (infestor + fungal growth).
If they're zerg they'll have about 50,000 zerglings.
Which get shredded by banshees and void rays.

If a Zerg player sticks to lings, they better finish the job or have a plan to switch to air if they're going to survive past the early game.
Man, the more I write about Protoss, the more I like them. Too bad I lack the skill to ever be very good with them.
