Catherine

First you must unlock Obelisk by getting 5 gold awards in the story mode on either Normal or Hard. If you have not done so already, then I suggest you check out the following achievement for more info.


---------------
Obelisk is approximately 220 steps and consists of every type of block expect for the black hole. As with the other Babel stages there is no set solution as most of the puzzle is randomized. Practice is key however, as a lot of the segments are repeated and it helps to know how to quickly solve certain patterns. Here are some general strategies that can help you conquer this level.

- A strong foundation is a must with this stage. To further clarify, you are going to want to try to keep your steps as wide and level as possible. If you see that your tower is becoming unbalanced, attempt to fix it as soon as possible, otherwise it will quickly spiral out of control.

- Don't be afraid to collapse entire layers. If there are only one or two blocks supporting the tower and your having trouble seeing your next move, feel free to get rid of them. Just make sure that if you have to push multiple blocks to collapse, then do so as fast as possible, otherwise you risk throwing off your foundation. Also note that removing layers will deduct from your overall step count, if you care about that sort of thing.

- Avoid bomb blocks if possible. They are probably the most annoying obstacle in this level as they normally come in pairs and triggering one will throw your tower completely off sync. There are some you can get away with stepping on, but just make sure you foresee the consequences before taking that risk.

- Same goes for the mystery blocks. These will become more and more common as you progress through the level and unfortunately they cannot be avoided. This means luck will be a huge factor with this level as there is no telling when a mystery block will decide to turn into a bomb. As always with mystery blocks, make sure to get off them as quickly as possible, in case they turn into a trap.

- Keep an eye on how far the tower extends below you. I found that this level tends to keep up with you more than the previous two stages and found myself running out of time on numerous occasions. Don't panic if it catches up with you, as once you pick your pace back up, you'll easily be able to put some distance on it. Just keep the time limit in mind when you have to pause to think about your next step or fix your foundation as it is a more prominent obstacle than in the previous levels.

- At about step 120 the path will split into two, this is where things can get particularly tricky. Start scaling whichever side you prefer, but keep in mind that you'll have to switch every so often. If you stay on one side the whole time, it will throw the tower off balance when the two paths eventually merge at about step 170. Just make sure to bridge across every so often and feel free to jump over if one side is becoming too complicated.

- If the level is proving too difficult for you on solo and you don't mind taking the easy way out, you can try beating the stage in Pairs mode. The game is local co-op only, so you'll need two controllers and also keep in mind that if one character dies it is game over. However, even if you are playing by yourself, this will make Babel significantly easier as each level is shorter (Obelisk is ~160 steps) and the puzzles are much simpler than in solo.

---------------
That about covers everything there is to this stage. Personally I found Obelisk to be much easier than Menhir, but that probably has to do with my preference with certain techniques and a great deal of luck. If I can think of anything else or if you have a suggestion, I'll make sure to add it. Also, if you are going to give the solution a negative vote, please leave a comment as to why.

The other solution is good, however I wanted to add a few things and post a video I made to help out a little more.
I think the easiest and best way to do this is with 2 controllers.
I put a pillow on my lap so the controllers didn't slide around and kept at it til I got it.
As you can see in the video, I barely made it.
Sometimes I would switch from this to Axis Mundi in case I was getting too frustrated, but patience and persistence are the keys to getting these.
I try to make each platform as flat as possible with a broad base even if it seems like I'm wasting too much time. This is more important on the later stages of Babel.
Watch what happens when you pull out or push a block out and what the consequences are. For example, when you pull out a block out from the end of a row, if the row above has an unsupported block that sticks out 1 block farther, that block always falls. That's why in the video I posted, I always try not to pull out a block on the end of a row if I can help it. Unless that will help me where it will fall.
Here is a page from the Catherine Wiki site with a lot of great advice on Babel:
http://catherinethegame.wikia.com/wiki/Babel_Tips
Even though it says elsewhere that the blocks are random, they aren't. There are only a finite number of combinations and there are only a relatively few different patterns that come up. You'll notice that the patterns are very similar from game to game. Not exactly the same, but similar.
I got this from the Catherine Wiki page posted below and above.
This page below also has some good info on Babel in general too including approximately how many steps for each babel level in both single and paired modes and a few videos on the single player:
http://catherinethegame.wikia.com/wiki/Babel
There are things to remember in paired mode. Both must survive and don't block your partners path. I know it seems obvious, but it's really easy to do.
Obelisk was the hardest 1 for me to do of the 4 levels of Babel. If you can do this level, the last level is easier IMO.
The key to this is patience and practice, if I can do it, so can you, good luck.