Originally Posted by Capn Doug
Oh, yeah, that was something I completely forgot to mention. Even with the unlock codes, not all spells are available at all times. If you want to keep them, you need to bind them to one of the buttons, since they can never disappear that way.
It disappeared even though I bound Fireball to B and Earthquake to Y button. I really think it's best to skip 5 times and then follow your walkthrough for best effect.
Also the linked artifact guide doesn't seem to have enough ruby & gold artifacts listed to get the achievement. The Great Gates (Darkness) level has the final ruby piece on top of stairs, and the final gold piece on the bottom of the stairs though. The Great Gates (Evening) doesn't have the Ruby piece on the left side (as far as I can see).
I think it's best for 10,000 kills to destroy one of the ghost generators and then go to the other one and just rubber band / turbo RT. Almost no ghosts will come your way and with regen 3 on it's impossible to die. It takes about 3-4 hours this way but you don't have to do any controlling so you can do it while you eat, study, work, nap, or playing games on WP7 for even more achievements.
One minor fix to playthrough 1. Underground Hall is the first level if you skip. Maybe switching the order of the levels around would be a bit more clear.
Finally, I'm copy/pasting the artifacts guide here, because this was useful for me when I played the JP version. This is in the ordered for the level skip and not the normal way of playing. (All credits to ms-xbox World. I only re-order and copy/paste their work with a very minor fix at the end)