If you're having problems getting the three star rating for a level you can lower the difficulty level to 'Casual'. Don't lower it to 'Relaxed' however because that doesn't count for stars or points.

When going for the developers scores and you come short of just a couple of points. Clicking the birds that fly over the screen will give you some extra points that may help you.

Anti-theft Speed

Prevent thief from stealing resources during a single level!

This achievement is kind of tricky and can only be done in one level as far as I know. That level is 3.8 Delicatessen. Other levels doesn't give you the opportunity to "control" the resource points from the start which gives the thiefs plenty of time to take whats yours. Makes sure to always have resource points in que for your workers and you should be fine. Remembe to que the berry bushes too.

Autolycos

Outsmart a thief by stealing something from him - right from under his nose!

This one is easely done with some proper planing and some reflexes. When you see a thief going for a resource point, get one of your workers there before the thief. The worker needs to be there whithin a second or so for this to work. Not recommended to do this at the same time as Anti-theft Speed should you miss getting there before the thief.

Champion of Champions

Earn every achievement!

Well, follow this guide and this should pop eventually :-)

Commander

Call upon 5 characters.

This one needs some serious work force to complete. For example, get Medusa to scare some cyclops, Hercules to remove some boulders and call 3 of your workers to do some work. All at the sme time. Other combinations can work to of course.

Note: A fully upgraded base (4 workers) and the extra worker bonus should pop this one to if you can get them to work at the same time.

Croesus

Collect 100 golds.

Level 3.1 Eye in the Sky will help you with this one since it's part of the mission tasks.

Demeter's Grace

Collect 100 resources of any kind with Demeter's Obelisk!

Some levels let you build a Demeter's Obelisk. At these levels you just need to start farming resources.

Double Bonus

Use 2 different bonuses togheter.

When you get the ability to use bonuses make sure you have two different bonuses to choose from. Let the bar get all the way up and use at least two in the same time, easy peasy. Some levels have tre bonuses with some of them far down the energy bar that really helps with this achievement.

First Gold

Complete 3 levels in Gold time

See Gold Chain.

Gold Chain

Complete all levels in Gold time!

You might think this is the hardest of them all. It is not. The levels in the beginning are the easiest to do although the levels later on isn't that har eather. If you still having problems you can lower the difficulty to 'Casual' instead of 'Expert'.

Juggler

Call upon 3 different characters simultaneously.

See Commander. This time though you can't use more than 1 worker for this to work.

Longbowman

Stop all aerial attacks on a single level within 3 seconds!

In some levels, bad weather will occure scaring your workers not to work. The clouds will go away if you click them a couple of times. Stay on your guard and be quick to click the clouds away within 3 second each and you should be all fine.

Overlord

Beat a Developer's Record 10 times!

Note: Turns out that you only need to beat 5 developers records to unlock this achievement.

This is probably the hardest of them all. In Hercules I and II you could simply play the first level over and over for this achievement to pop, not this time tough.
Here are some levels that I did complete and some tips and tricks for you to use:

-Level 1.1, Megara's Gardens, see Superior

-Level 1.2, Outpost, I only cleared this on by a few points. I was clicking a lot of birds and
focusing on the bushes to have a sufficient food in the end. All the trees are needed do build the last bridge.

-Level 1.6, Opticist, actually I don't know how I did this one. I found some kind of flow apparently :-)

-Level 2.1, Hermes Speeds you, speed is the key in this level.

-Level 4.5, Mountain King, when you get to the top T-junction, don't bother going to the left for the resources. No need to get Pegasus to push the stone into the pit.

-Level 4.8, Start by going up towards the meat and right towards Apollos Obelisk. Get meat asap then get wood and upgrade house while also clearing a path to Medusa. stacks of wood are faster then chopping trees, but you will need some anyway.Get medusa asap then get Apollos obelisk completed. After that its gets a bit hectic but prioritise respawning coins over static ones.
Thanks to Azatoth for sharing his comment.

If you have any tips of any levels suitable for this achievement, leave a comment down below how you did it. Thanks.

Persistence

Use the same bonus again before its time runs out.

When the bonus energy bar is full, use a bonus that is on the lower half and simply click it twice.

Puzzler

Find 5 puzzle pieces!

govegirl has a wonderful guide on were all the puzzle pieces are located on all the levels. If you can't find them yourself pick some levels from that guide to pop this achievement. Link bellow:
http://steamproxy.net/sharedfiles/filedetails/?id=495832958

Road Worker

Remove 4 obstacles using the "Work Faster!" bonus!

When you get to a level with the "Work Faster!" bonus. Save up enough resources to take out 4 obstacles on the road. Activate the bonus and watch your workers do the work.

Speedster

Activate the 'Run Faster!' bonus with a complete Hermes' Obelisk!

Some levels will have the possibility to build the Hermes' Obelisk! and let you use the "Run Faster!" bonus. Just build the obelisk and use the bonus to make your workers get super speed.

Strategist

Complete a level in Gold time without using any bonuses.

You can do this one on 'Casual' difficulty but it shouldn't really be a problem on the higher difficulty levels too. I would go so far to say that you can complete all the levels without using any bonuses, but don't quote me on that :-)

Superior

Beat a Developer's Record!

The first level is the easiest level to do this on. Make sure all your workers have a full que and that the berry bush gets activated as soon as possible. When the workers are doing all the work, click some birds to get extra points. Make sure you set the difficulty to 'Expert' to get maximum points.

The Golden Mean

Complete 20 levels in Gold time!

See Gold Chain.

The Greatest Challange

Complete the super-bonus level in Gold time!

See The King of Midas. The name of this achievement is a bit misleading because this in far from the greatest challenge of all the achievements in this game. Time consuming perhaps but not much of a challange.

The Kingdom of Midas

Complete four bonus levels in Gold time!

First you have to unlock the bonus levels. This is done by finding all the puzzle pieces, seePuzzler, and solving the puzzles. The are not very hard. When the bonus levels has been unlocked, it's just a matter of completing them in gold time.

Note: When this is done, a super-bonus level will unlock, solve this in gold time to get the The Greatest Challenge

Trickster

Servant must collect one resource once all objectives have been met.

This should come naturally when you play the game. You can help it a little by, for example; when you have a pointer that need to be fixed, save it until all your resources on the level are ready to be collected. Send a worker to the pointer and when he is half way there, send your other workers to collect the resources. This should pop the achievement.