I've come to enjoy playing Queen a lot. Several Queen builds/guides have sprung up, probably due to the fact that the character overall has a fairly indirect playstyle. Most players likely will think that my build and style are no good, as it is not specialized. I feel this is something forced upon the Queen, as out of all of the characters her "best" function is situational. She doesn't directly support other demi's as well as Sedna, she doesn't AE as well as Torch, and she doesn't camp as well as Rook. She can't harrass as well as spit UB or several other characters, and she isn't good at ganking or punishing someone that overextends. The only thing she does better than anyone else is drop towers fast with the armor debuff from Ground Spikes; pretty marginal and situational.
However, if you look at all of those things, Queen can do them. She can support another demi both offensively and defensively. Her AE is good, and she can camp creeps pretty safely. She still has range and a situational snare, so she can harrass. My build plays on that jack-of-all trades aspect.
*Big Picture Build*
-Game Start-
Level 1: Shambler I
Level 2: Bramble Shield I
Level 3: Ground Spikes I
At game start, change forms, choose Shambler, summon one. Then go ahead and grab your favor item. I usually choose Blood. Grab your Banded and whatever else you like, summon another Shambler and move out. Early game is like anyone else, cautious kiting, positional petting, harrassment. Stay in closed form at all times. Do not cast the first rank of spikes, ever. It's a waste of mana. You are just using auto-attacks and pets to creep, auto-attack demis to harrass. Avoid using shield as much as you can. Use pets to scout and help burn creep waves.
-Early Game-
Level 4: Ground Spikes II
Level 5: Spike Wave I
Level 6: Mulch Shambler I
Level 7: Ground Spikes III
Ground Spikes is your most important skill from this point in the game forward. Everything you do should be based on whether it is appropriate to Spike. This is when kills can happen, be ready for them. You still aren't likely to score one, but get in positions to help flank or force someone into a flank. You'll want to Ground Spike to hit demi's and then auto-attack 2-3 times before deciding whether to pursue or retreat. If a target is low, you'll want to Ground Spike followed by Spike Wave before the autos. This is your burst, and your main kill method.
This is when Queen starts to get more complicated. You should be in open form a lot from now on. The only time you should be using closed form is when you are by yourself or you are low on mana or health. If you are with a partner, shield them and then switch to open form. Your allies should keep themselves alive, they should never rely on you to chain shield them. It is better for you to be aggressive and add pressure than to sit back and cast shield. However, if you aren't in combat (remember closed when solo) and someone retreats toward you, wait until their in range, hit em with a shield, then open and add pressure. Spike Wave is also important to use both as a peel and on the approach. If an ally is running toward you and you're in open form, don't try to swap so you can shield. Run straight to them and Wave through as many demi's as you can, then hit Ground for pressure. Depending on your allies health he can turn and utilize the debuff. You can do this at the start of any battle as the target(s) approach you. You'll get an extra hit or two on them before they reach you.
You should almost never use Mulch at this point. It is a desparation move, but an important one. It allows you resist easily getting ganked solo. Spamming Shield and Mulch on yourself is a big mana drain, but it can sometimes help you survive tough encounters. You can also use Mulch to creep a second wave, but with rank 1 it takes timing. You need to get the killing blow to get the exp from so far away, so if you have time then position the shambler and wait a bit for the creeps to damage one another. Mostly not that great at this level, depending on the map.
Your mana useage is intense in this phase. It's important to get enough regen to maintain, but not at the expense of max health and speed. I personally like both Boots and Wand of speed, obviously Vlemish is great (and you get a lot of regen in closed form). Also getting Unbreakable and Nimoth are good choices. Using mana potions is a very good option. I often grab minotaurs early as well, as they are super cheap to cast. I just use them as expendable scouts along with my shamblers.
-Mid Game-
Level 8: Save
Level 9: Save
Level 10: Ground Spikes IV, Spike Wave II, Mulch Shambler II
Level 11: Bramble Shield II
Level 12: Bramble Shield III
Level 10 is huge. You should be trying to win in here. Keep watching your surroundings, watch the big picture. Hold the main lane(s) and lay heavy siege to the other teams' structures/perimeter. Restrict their movement while maintaining a frontline stronghold for your allies to come to for shields or to team up for kills. Flank overextended players. Begin killing structures in earnest. However, avoid the temptation to sit on any tower. Ground Spike a tower, hit it 2-3 times and back off. Wait to see if someone portals or runs over to defend, and proceed. Never chain Spike a tower or you run major risks.
If there are two open lanes, Mulch is now easy to snag waves with. Use it. Mulch also adds a complicated back loaded burst to your arsenal. It's terrible to manage, easy to avoid, and mostly not worth using. However, it can work. Summon a Shambler and immediately press the key to select your special minion (I remapped this to R). Target it's move behind your target, usually the Shambler gets summoned far enough away from your target that it won't hit it. Mulch it. Immediately switch forms, Ground Spike, Spike Wave, auto attack 2-3 times. This works best against melee targets. The Mulch hit will happen just before or roughly when the Ground hits, generating a reasonable amount of damage. I only do this when I'm solo, since that is the only time I am in closed form and not desparately trying to survive. You can also retreat a couple steps as you Mulch, instead of moving the Shambler before Mulching. This is safer, since the Shambler dies very fast if it takes damage. It's more important to get the Mulch off than to get the Shambler positioned. Once you hit Mulch, shift forms and move while you are shifting, then Spike.
You should be getting catas and giants in here or soon. You support creeps very well with your armor debuff and the ability to clear out enemy waves fast. Fight in the midst of your creeps whenever you can. Try to get several things impacted by Ground Spikes at once, as creeps target so haphazardly. If you can get a tower, a demi or two, and a wave of creeps all in one cast then you are at a big advantage.
There is a lot of controversy about the Heart of Life. I personally get it. Along with Vlemish it covers your mana, which lets you stack up health and speed in the rest of your slots. I tend to save money toward giants and upgrades as much as I can.
-End Game-
Level 13: Bramble Shield IV
Level 14: Save
Level 15: Mulch Shambler III and Goddess of Thorns
Level 16: Uproot I
Level 17: Compost I
Level 18: Uproot II
Level 19: Compost II
Level 20: Compost III
Most games don't get this far, but when they do I add Uproot. Mulch is a weird sort of powerhouse in certain sitatuations at max rank, and Goddess is good when you're on offense spamming Ground Spikes. You should be in open almost all the time at this point in the game. Uproot will almost never be used. With Ground Spikes you won't need it to decimate a tower. The trick is, if you've gotten to this point in the game and you're in a position to win, then the other team is stalling. Casting Uproot let's you hit towers that are defended well enough that you don't want to attack them. It also allows you to wittle away at the citadel without directly investing time in that. You want to be fighting in their base, using your creeps as shields, Ground Spiking all the time. Switch forms to tank with Mulch/Shield, but avoid this unless you're desparate.
At this point, if you are farming tons of money but can't win, you should buy auto-attack increasers. Ashkandor+ is quite good after the debuff from Ground Spikes.
If you are on the defensive, they have you at your citadel, and are farming their creeps, then you will probably want to tell your teammates to go on offense while you try to hold them off. If you are on defense in this situation, you'll want to chain Mulch and chain Spikes. Just keep doing your Mulch + Spike burst move to kill creep waves and heal yourself. After your Spike, auto attack a demi once or twice before switching forms to prepare to do it again.
-Spec Notes-
I choose not to get rank 3 of Spike Wave. It increases the cooldown in exchange for more range/damage/snare. I do not feel this is worth it, as getting the snare effect at all is the important part. I get Compost at the end because it makes Uproot damage significantly more efficient per mana.
-Separation Mindgames-
If you use Spike Wave and Mulch effectively, the opposition will get used to how you are using them. They will start running through your Mulches and/or retreating from them. They'll sidestep your Waves. This can be used to your advantage. Mulch and run in an unexpected direction to gain separation. Be spontaneous. Start summoning shamblers just to make the enemy run away when they see it, then you don't even have to Mulch. When they start dodging Waves, move as if you're going to cast but then just don't. Make them waste time sidestepping for nothing. You've created more time, more separation by doing this, which gives you advantage.
That's it. I realize this is a massive wall of a guide. If you've read this far, thanks

Good luck, Queens!