I classify Droplitz as an intermediate puzzle game which requires a lot of training and quick thinking. I'll be including some tips and tricks to help you get the achievements. Please note though...it can take some time. It's required to master the game as well in order to get through.

Difficulty: Very Hard
Achievement Description: Survive for 2 hours.

Earning Notes: This is highly recommended to be done on Zendurance Mode. Time consuming, and one long thought on the next path can cost you.

Difficulty: Medium
Achievement Description: Stack 3 Chain Reactions

Earning Notes: Whenever a path disappears once completed, and a new path is created without making anymoves, it is called a chain reaction. Try manipulating the discs to easily make a new path for the next drop, or once the discs start(and during) disappearing, move the discs to make a new path. It's best to practice these chain reactions for your multipliers and high scores.

Difficulty: Hard
Achievement Description: Create a multiplier of 35 or more.

Earning Notes: Multipliers are tough to earn. It is a combination of more than one path and lots of chain reactions. Save a Dropper Disc that is on the bottom or near a path to give you more time to make possible paths. Highly recommended to play this on Big Expectations in Classic Mode.

Difficulty: Hard
Achievement Description: Unlock all boards in all modes.

Earning Notes: Even if you mastered the game well, the score to unlock boards can be a challenge.

Difficulty: Easy
Achievement Description: Create 40 paths.

Earning Notes: Simply make 40 different paths. A basic achievement earned while playing.

Difficulty: Easy-Medium
Achievement Description: Use all Droppers and Collectors.

Earning Notes: Play on a small or medium board on easy difficulty. This is another basic achievement you can earn while playing. Just make paths on all droppers to all collectors. If you see the text "FULL HOUSE" come up, you should be able to get this achievement.

Difficulty: Medium
Achievement Description: Collect 5 Droplitz with no path

Earning Notes: This is one of those 'uncommon' happenings in the game. Sometimes you will get stray droplitz that aren't in any path, but are heading to the collector on the bottom. Try leading the droplitz that remain into the collector before making a new path.

Difficulty: Medium
Achievement Description: Unlock all themes.

Earning Notes: On Classic Mode, you will go through many different themes. Go through all 9 of them to unlock this achievement. I recommend an easy board to do this.

Difficulty: Easy-Medium
Achievement Description: Score 250,000 points

Earning Notes: Do it in Zendurance mode. If you're going for the Completionist achievement, you will come across this achievement since some boards require you to unlock with this score or more.

Difficulty: Medium-Hard
Achievement Description: Score 1,000,000 points

Earning Notes: Again, best to do this in Zendurance mode.

Difficulty: Medium
Achievement Description: Survive for 20 minutes

Earning Notes: It's best to do this in Zendurance mode.

Difficulty: Very Hard
Achievement Description: Create a multiplier of 50 or more.

Earning Notes: This makes Adventurer and Combo 35 a walk in the park. Use the tricks provided in Combo 35...instead this time, you will need luck for this one too.

confuted - For advice on how to get the 'Zen Master 50' achievement. (source)

https://www.ko-fi.com/jilloftrades