This achievement requires skill, but here are a few exploits to make getting it easier:
btw, the architect is the old guy with the glasses outside the castle right before you go up the stairs and cross the drawbridge to death. Using him will prevent the castle from randomizing keeping the exact same layout as your last life. OBVIOUSLY DO NOT DO THIS, OR IT WILL VOID THE ACHIEVEMENT.
If you're having a bad run and have died too many times and want to scrap your save and start over, your runes and armor blueprints will persist between saves AS LONG AS YOU DELETE THE SAVE IN-GAME
(from the title screen, press
, highlite your save and press
to delete). I'm not entirely sure if everything will carry over, but I had all the collected runes and blueprints appear in my new save.
Unlock and max the Gold Gain Up stat ASAP. I'm not entirely sure what you need to buy to get there, but it is in the lower right corner of the castle. I think you need to buy the miner class for it. Its right below that.
Save scumming: basically reloading your save if you die, which Rogue Legacy basically won't let you do. You will be safe from having the game save and upload to the cloud as long as you disconnect from the internet BEFORE moving on from the death screen displaying killed enemies. After disonnecting from the internet, from the dashboard, you want to highlight the game and press
, select quit. Press
again and go into Manage game & add-ons and delete the save. Make sure the save is completely gone before reconnecting to the internet and restarting the game. If you did everything right, you'll resume playing as the character who died.
Save scumming for lots of money: basically you're looking for a Cheapskate Elf room. He's the guy wearing a white cloak standing in front of the 3 treasure chests. If you're really lucky, you can find 2 of him in 1 castle. Anyway, you want to have as much money as you can before you play his game, so play through the areas you're comfortable with (without dying easily). Once you're satisfied, save and quit. Then dashboard, press
on Rogue Legacy and quit the game. This will upload your save to the cloud. Restart the game, and go to the Cheapskate Elf. If you lose his game, disconnect from the internet and delete your save. Reconnect to the internet, start up the game, and try the elf again. Be aware the winning chest is not set, it is always random. The only way to know which is the winning chest is to start with a character that has a sight disability and getting the glasses item from a statue. The glasses reveal the winning chest. Anyway, this will give you lots of money far faster than the other solution.
Arguably the most OP class in Rogue Legacy is the knave/assassin. If you max out crit chance and crit damage on your castle, and have the slayer set on him, you'll be an OHKO machine. Loading him up with vampire runes will make the castle a cinch as long as you aren't terrible and soak up too much damage too fast.
I'm not sure how the game keeps track of deaths. I beat the game on my 13th life, and the final post-credits screen said I had 11 total children.
Again, this achievement requires skill. If you can't beat the first boss and survive the forest area within your first 5 lives, you're going to have a rough time of beating the game wtihin the first 15 lives.