Tactics

This is an easy 200 points, with even a glitch to help you get a hard achievement! Interpol : The Trail of Dr Chaos is just a "find the hidden object in the picture" game, so all you do is point and click.

There are 11 missions in the game, each with three city locations. Some missions include an extra locked puzzle. You can play co-op with a friend, however I wouldn't recommend it, as it seems to be glitchy with some achievements not unlocking if you play co-op. 

There are hints you can use if you get stuck. However there is an achievement for completing the whole game without using hints. Use the hints if you are struggling and remember where the object is, then just go back and repeat the mission without using hints. The game will always save your last mission. There are also 3 hidden bonus items which increase your time limit, add bonus points or add an extra hint. Be aware that if you do replay the mission, the objects do slightly change, but not by much.

One final note. Don't expect clear HD pictures either. Some are annoying because they are tiny and the clue is not all that clear.  

ACHIEVEMENT GUIDE

Finder's Keepers - 20 points

Find all 8 Items in a City Location in the Single Player or Co-Op Mission

You should receive this after the first location. You need to find all eight items. Some clues give multiple items eg 2 pens. This counts as one item for this achievement.

Quick on the Draw - 10 points

Find 3 items within 5 seconds

Sounds hard, but you will probably get this on the second or third location, once you get used to the controls. If you can't get it, just repeat a mission you just completed and you should remember three items. Multiple items count (eg 2 pens count as 2 items) for this achievement. 

Bonus Plan - 10 points

Find all 9 Bonus Items in one Mission

Bonus items are objects not included in your clue list. There are three in each location, so there are nine all together in each mission. They are the same object (eg a hand of cards) in each location, but change with each mission.  

Not Impossible - 10 points

Complete one Mission

To complete a mission, simply find ALL the items in your clue list for each location, within the 30 minute time limit. Some bonus items you find, can give you extra time. You should get this after your first mission.

The First Hint’s Free… - 10 points

Complete one Mission without using any Hints

Simply do not press the "Y" button (hints) at all. If you did, just replay the mission again without any hints and it should unlock

Just Said “No” - 25 points

Complete every Mission without using any Hints

Some people have had trouble unlocking this, with some replaying the game several times without hints and it will not unlock. This achievement will also not unlock if you have played it in co-op without hints.

My suggestion is if you play a location and use hints, replay the mission again, without hints. The game always saves after a mission.

I personally unlocked this by replaying the entire game again and doing the locked missions, without going anywhere near that "Y" button. 

Wham, Bam... - 25 points

Complete a City Location in less than 30 seconds

Hard if you were going to do this legit and in fact it will NOT unlock if you do! This achievement is glitched and fortunately you can unlock it without the need to go crazy trying to beat the clock.

After you complete the Tokyo mission there are two bonus puzzles (in single player only). Simply complete a bonus puzzle and the achievement unlocks.  Take your time, I took around about 5 mins and it still unlocked.

Some people have suggested you may need to actually do a location in 30 seconds and THEN do the bonus puzzles, for it to unlock.  I never did, so it is up to you if want to do it.

Star Performer - 25 points

Earn Elite Agent Rank in any Mission

Hardest achievement of the game. Best to go to a mission and replay it several times until you become quite familiar where all the items are. To earn Elite you have to score a lot of points and complete the mission in good time, so you have to be quick.

The trick is to collect ALL the bonus items FIRST before collecting any other item. The 1000 point bonus will continue with each next item you pick, if you pick them quick enough. The extra time bonus will give you more time and thus you are finishing in record time. The extra hint item will give you an extra hint not used and add extra points. You have to do this with each location, so try to pick a mission without a locked location.

Do not mis-click at all, or it will count against you!

Credit goes to KloonsDead for the hint. 

You Always Remember Your First - 10 points

Complete Mission 3 and capture Mister Smith

Just complete Mission 3.

Back for Seconds - 15 points

Complete Mission 6 and capture The Hammer

Just complete Mission 6.

Third Time’s the Charm - 15 points

Complete Mission 9 and capture The Artiste

Just complete Mission 9.

Fourth Down - 25 points

Complete Mission 11 and capture Dr. Chaos

Just complete Mission 11.