This achievement unlocks after you have finished a game in Challenge mode in which you unlock all 11 additional skins for Base. Take your time dropping pieces, but try to concentrate your pieces into the middle 2/3 of the screen so that you have some area to work with on the sides should your stack become to high. Once you have made your way back to the first skin (you'll recognize it as having orange/white blocks and a spinning red target in the background) feel free to sabotage yourself to end the game and get your achievement.

You will inevitable get this while clearing Base, but note that if you quit the game you will not get the achievement. You must finish (i.e. mess yourself up) in order to unlock the achievement.

See "Time Attack 60sec. : 70 blocks".

See "Time Attack 60sec. : 70 blocks".

See "Time Attack 60sec. : 70 blocks".

Time Attack 60sec. : 70 blocks

Probably the hardest achievement in the game. You can get a good idea of what is needed to achieve this lofty goal by looking at the leaderboards for Time Attack Mode 60sec., then downloading the replay data for some of the top players. To watch this replay data you need to go to the Replay Theater within the game's Option menu. As a general rule for all of the Time Attack achievements, start from the left and build your combos to the right as fast as you can to avoid the "timeline".

See "Time Attack 60sec. : 70 blocks".

See "Time Attack 60sec. : 70 blocks".

See "Time Attack 60sec. : 70 blocks".

Once you have mastered Time Attack this should be no problem. Use what you learned, but slow it down considerably if your stack becomes too tall and concentrate your efforts on ridding the screen of blocks rather than creating large combos. You may play through all of the skins twice before getting this score, so plan on playing as long as 45 minutes to get this achievement. As with the last 2 achievements, you must finish in order to unlock this one.

Another hard achievement. You must assemble a playlist of 10 skins, then race to get the score before you run out of skins. It is STRONGLY recommended that you buy the Advanced Pack and unlock all of the skins in the game before attempting this, as you can more or less "cheat" by using all of the slowest skins in your playlist.
The slowest skins are:

Meguro
Holiday in Summer
Big Elpaso
So That Someone May Visit You
You should use these 4 in conjunction with any 6 of the following:

Circles
Morning Beats
Take a Dog Out a Walk
Aoi
The Mission to the Moon
Shadow of Grandfather
Mysterious Travels to Asia
HIKARU FRAMEWORK
Fanatic

If you don't have/can't get the Advanced Pack you will have a much harder time, and the best advice is to use all available skins minus Just and Strangers.

Once you get your playlist sorted and start playing, keep in mind the advice for Half Million. Good Luck!