Alright. To let you know immediately, until you realize how exactly this boss works, it will be the most toughest, and possibly the most aggravating Super Sonic-exclusive boss you might ever come across. In fact, I think it still is for me.
That's right. Doomsday Zone, Perfect Chaos, FinalHazard, the Moon, True Area 53, Metal Overlord, Nonaggression Gemerl, Devil Doom, Egg Salamander, Solaris, Egg Wizard, Perfect Dark Gaia, Nega Mother Wisp and even Time Eater (HD) have nothing against Time Eater (3DS). While the HD version was annoying because of the constant "THAT'S A HOMING SHOT! CAREFUL SANC!" and the difficult-to-pull-off "Can't Touch This" achievement/trophy, the 3DS version can appear as either well done or unfair.
Now some of you may be asking yourself: "VizardJeffhog, you ruffian, what the devil are you speaking of?" while some of you may already be agreeing with me. Here is exactly everything you need to know prior to fighting this guy.
First off, Rings.
Unlike past Super form-battles, you start off with 100 Rings. You'll soon come to realize that Sonic Team/Dimps have been very generous with you, seeing as Rings don't appear very often during this fight, not to mention that you will be held off by constant onslaughts of the chronophage.
The first two hits should be done without too big a problem. However, from the 3rd hit onward to the 7th, be sure that you will have enough hair on your head to pull off.
Every time you land a hit in the 2D sections, a massive amount of rings will appear! Technically, if you don't touch anything, you should be able to draw a massive portion in.
As for 3D, there will be rings grouped in a circular pattern. However, it will get tougher keeping attention on these throughout the battle. More on that later.
Secondly, in the 2D parts of the battle, every time you get hit by any of the Time Eater's attacks, that same attack will be repeated. So, if you've been hit by the Homing Shots, the Time Eater will send more of them. If you've been struck by the thin green lasers that start to come by after the 2nd hit, the attack will be prolonged. If you've been hit by a giant energy beam, the Time Eater will do it again. You don't get hurt, but it keeps away any possibly Ring you might be getting. What you will need to do is dodge attack after attack and pray that Rings will show on the screen and that you're directly in their path, but their appearances are extremely rare and distant (time-wise) in between.
All I can tell you here is to dodge, dodge, freaking dodge. For the Homing Shots, approach the Time Eater onto either the top or bottom corner and fly around to maneuver in between the attacks or just around the screen and avoid their direction. As for the green lasers, stay on either the top or bottom right corner (against the Time Eater again) and move if the orbs that will shoot said lasers appear right where you are. Finally, the giant laser/energy beam: follow the same instructions as shown with the small green ones. Take note that more and more green laser orbs will appear as the fight drags on, going from one to about three, now making it harder to dodge.
Finally, when in 3D, there is one thing you must worry about, and this is maybe the most frustrating element in this fight. The arms. They don't appear the first time you go into 3D, but the second time onward, the Time Eater's arms will keep shoving you further and further away from your target: boosting is futile. You will have to stop and move around using the B button to keep away. The arms bash against you pretty freaking quickly, and if you're already too agitated, either calm down or put the game down and take a break. Gather your wits, keep calm, keep your reflexes sharp, then go ahead and keep dodging the arms. Keep in mind that their movements might be incredibly unpredictable at times.
Again, the fight drags on, more rings are lost, and you might already be past the point of no return where the only remaining option is to wait for your dwindling rings to hit zero and/or restart.
The Time Eater also possesses another attack in 3D in the later part of the battle which involves the creation of a clock. Basically, avoid the big and small hands of the clocks he sends to you and get to him.
As for the final phase, it should not be too difficult. Just dodge the green lasers and aim for the Time Eater!
If anyone has anything to add, please do so!