hum...the type 0 cards are a bit underpowered since they're hard to summon.
The mansion could be a bit overpowered since it lets you summon any monster with 2000 or less DEF from your deck with pyramid turtule, but it's not that bad since zombie world can't be at the same time on the field.
The other cards are ok, I'd advise you to check the ygo gramar thougt. Also, type alpha should be an union monster.