Okay, huge spiel coming. (I’ll answer your specific question first, though.)
Generally speaking, you can play all the way through to the level cap without ever needing a team. The only time a team is explicitly required is on Task Forces and Strike Forces, which are special story arcs designed for team play–you have to have a minimum number of people on a team before the contact will let you start. Even so, I’ve soloed the first task force in Heroes with a Trick Archery defender (think Green Arrow), which is considered one of the weakest soloing builds. (Admittedly, it was very painful, and I did it only to prove a point.)
The bulk of the missions in the game are instances. They’re scaled to your level, the size of your team, and your difficulty setting. A solo hero on the lowest difficulty setting (Heroic) will typically face groups of three even-level minion-class enemies in a spawn. Bosses don’t spawn on Heroic–the “boss” spawn in the mission will be a lieutenant instead. Elite Bosses–unique characters who are generally supervillains or the leaders of criminal organizations–will spawn on any setting. They’re substantially tougher than bosses but still soloable. Your contact will usually warn you that a mission with an Elite Boss will be tough, and recommend taking a team. With a team, or on a higher setting, more enemies spawn, and they spawn at higher levels.
The balance of power is very much more in the player’s favor than in WoW–the idea is that you’re playing a superhero, and should be able to wade through swarms of flunkies before taking on the big guy, so the original idea was that 3 even-level minions was a fair fight for one hero. That’s true for the less solo-friendly classes (archetypes) at low levels; at high levels, 3 minions is a cakewalk for pretty much any character. This contributes to the fast-paced feel of the game.
Movement definitely bears a mention, since I’ve been playing WoW a bit this week. You start off moving as fast as or faster than a WoW character, and one of your inherent abilities is Sprint, which makes you noticeably faster as long as it’s turned on. At level 6, you can open a travel power pool, but the first-tier travel abilities don’t make you much faster (Hover lets you fly at about walking speed, and Combat Jumping lets you hop around a bit farther and faster while protecting you from being immobilized). At level 14, you have access to a travel power–flight, super speed, super jumping, or teleportation. At this point, you can move around much faster than in any other MMO I’ve tried, and the powers get faster with level and with slotting. Most zones also have at least one monorail station that will take you to a bunch of other zones–picture having a portal in Ironforge that opened onto every other Alliance capital. There’s also an interdimensional nightclub that serves as a travel hub, and SG bases can have telepads that link to every zone. Travel in City is very, very fast.
City’s character creator is its pride and joy; you can look like almost anything from the moment you create your character. (There are some special things, like wings or rocket boots, that you have to unlock, but those pieces are in the minority.) If you play a character that uses a weapon, you can customize the weapon’s appearance somewhat at character creation or at the tailor, but the effect of the weapon doesn’t change. It’s not loot, it’s a facet of your character.
Gear is different, too. In a sense, there isn’t any–no weapons, armor, jewelry, or what have you. Instead, there are enhancements. Enhancements are used to increase certain aspects of each of your powers. If a particular attack is missing too often, you slot an accuracy enhancement in it. If you want it to be usable more often, you slot it for recharge. You get enhancements from drops, from stores, from the auction house (actually consignment house or black market) or from crafting them.
The City analog to potions is inspirations. They drop from mobs and can be purchased from stores and contacts. They can heal you, restore endurance (mana), increase your defense/damage resistance/accuracy, break you out of a mez, or resurrect you on the spot. They take effect instantly, and there is no cooldown, but most of them last less than a minute.
There are no crafting skills as such. If you have a recipe and the salvage (materials), you can craft the item. You can craft enhancements, costume parts (which unlocks the part permanently for that character), and temporary powers. Even the generic crafted enhancements are better than the ones you can buy, and there are special enhancement sets that give extra bonuses. You can buy all the generic recipes at a crafting station if you don’t get what you need from a drop, but the set recipes are only available from drops or from the auction house.
