In Desktop Dungeons, I've been having a hard time getting the Wizard to survive the Factory challenge and get my final unlock. Is there any particular method that works best for beating this level?
The most ideal goal involves finding two things as early as possible: a level 8 or 9 Animated Armor, and either BURNDAYRAZ or CYDSTEPP. You can see glyphs so it won't be too hard to get these early enough. Since Animated Armors use Death Protection instead of real Health, you just need to slam it 9 or 10 times with your spell, gaining experience to hit level 5 in one shot. In a normal scenario you will probably have uncovered some other high level armors as well. Always soften them up with your spells in between physically beating Meat Men and Golems. Your goal is to have a bunch of Animated Armors with no Death Protection left that you can use to gain levels in the middle of fighting the bosses. Take on Meat Men of around your level, and Golems of just below it, while setting up the Animated Armors. And make any additional 8 or 9s priorities to kill for experience.
Counter to intuition of what wizards usually do, you actually stand a better chance by playing this from a physical approach. Play a human to convert any less usable glyphs for an Attack bonus to offset your penalty as a wizard. Shops that sell Attack, Health, and Physical Damage Reduction items will be ideal, but the most useful item you would want is the Venom Blade. Works great against Meat Men and especially Super Meat Man, but it's also important because it doesn't have a chance to fail on The Iron Man.
You'll then be conserving your mana primarily for BYSSEPS and/or HALPMEH during fights, which your reduced cost helps a lot. Even without the poison, you can still take on The Iron Man fairly easily with these and mid-fight leveling at around level 7. Conserve your health potions for Super Meat Man.
God choice in the factory for the wizard is not nearly as important as good item luck. It's tempting to play Mysteria Annur, especially since the new power includes destroying all magic resistance of golems. However, the absurd Health of the Meat Men and Super Meat Man is a much larger barrier, combined with the fact that Mysteria no longer gives such a huge bonus to Mana. Having some measure of physical damage is really useful. Unless you've already killed Super Meat Man (by, say, early-game poison), in which case you can use it to utterly ruin The Iron Man with BURNDAYRAZ. Failing early termination of Super Meat Man The Pactmaker or Glowing Guardian make excellent choices. GG is good for two full-heals during the middle of your fight against Super Meat Man, while The Pactmaker gives you some bonus Health and Mana and a potential level up.