It would be a relief to me if the vision fields are optional. The conditions imposed on them make them into a twitch fest where perfect timing is more important than strategy. To me they just seem out of place.
Aside from the first try on V4, V1 and V2 were fairly easy.
V4: Enrage. Some people ease through without summoning extra monsters, but you need it here. Figure out how much you can enrage with which gem to maximize mana profit, which lets you pump enough mana into towers to defend your orb with. Make certain you have Armor Tearing in your main gem to strip the "surprise" enemy, or you'll just go on forever.
V1: There's a trick/cheat to this one. Ctrl-click to summon all waves early, and don't bother building anything. (Unless you want to get Achievements.) You can just freeze at will. You'll understand when you try it. Anyway, I did it the "correct" way the first time, so normal combat style does work.
V2: Same trick might work, but I didn't need it. Build smart, so that new monsters have to go to your first Node. You want to lead the Node, so that the cursed monsters walk into, then out of it's range, that way you get max time in range. As things get hairier, you'll have more monsters on the field, and nodes will gain charge even faster.
I don't have any of the others yet. I can see there's one to find on the U grid map, for instance.
V4 doesn't have armor tearing, though - only poison and crit. You do have access to amps, though, so amping crit chance can counter the rising armor of your foe. Also, use bolt wisely!
