All secret achievements and how to get them

1. Castle victory- Checkmate your opponent by castling.

This is one of the toughest achievements in the game. Take all your opponents pieces and trap their king in the centre files and then castle. 

*You could ask a friend to help you achieve this in a unrated friendly match*

2. Full House - Win without losing any of your pieces

This is impossible against the high rated players and most people have achieved it in their beginner phase. Scholar's mate is recommended for low rated players.

3. Killer King-Checkmate by moving your king

Capture all your opponents pieces and trap the opponent king in the last file with a rook/queen. Place your king in the same file and another rook/queen behind the king as in the picture. Move king to b8 square to get Killer king. The setup in the picture is required.

4. Nick of Time- Win with less than a second left on the clock
Play a lot of bullet and stall until the last second if you have a checkmate. This one is pretty easy.

5. Full Day- Spend 24 hours doing puzzles
You should spend one hour in each puzzle and do 24 puzzles that way to speedrun this achievement. You don't have to do it in one sitting as it is cumulative.

6. Searching for Bobby Fischer-Search for Bobby Fischer in the Games Database. 
Click the search icon in the left side of your screen and search "Games Database" and enter the name of Bobby Fischer in the player field and click search. This is the easiest secret achievement.

Christmas achievements: Only possible to obtain in December (Dec 3- Jan 6)
7. Precious Snowflake- Defeat Powder the Snowman (800 elo bot)
8.Nutcracker-Defeat Eve the Elf (1000 elo bot)
9.Full Stocking-Defeat Santa (1200 elo bot)
10.Jingle Bell- Defeat Dash (1600 elo bot)
11. Holy Berry-Defeat Mr. Claus (2000 elo bot)

*You get the achievement even if you one crown the bots so you can keep using hints*

12.Juggler- Play 20 daily games at once
Accept 20 daily games and you can abort them after you get the achievement. This one is also very easy.

13. Chess Marathon-Play a game with over 100 moves

This achievement is more common in high rated games which are very long. But you can still ask a friend to lend a hand in a unrated friendly game as randoms usually resign.

14.Good Read- 100 people read your blog 

100 people have to read one of your blogs to get this achievement. Since there are so many blogs out there, this one might end up taking the longest.

15. Good Habit-You did puzzles 7 days in a row
16. First-You commented on a Daily puzzle
You need the chess.com app on you mobile and go to forums. Click daily puzzles category and hit search. Send a message and you will get the achievement.
17. Man vs Machine- You battled a bot in Live Chess.
You can no longer get this achievement.