Tips and Tricks

Ace Point Grinding
Video http://www.youtube.com/watch?v=Vxit58H7IAY
 * Stage: A01
 * What you need: At least one MS and two warships. Finishing the stage with two full warships and an MS will net 51 Ace Points to 13 characters each.
 * What to do: There are 3 enemy units on the stage. Kill one with your MS and one with each of your warships. Make sure Amuro doesn't kill Char, as it will trigger the Generation Break.
 * PROTIP: You can just place your pilots as crew if you want them to gain Ace Points instead of your regular crew.

Level Grinding

 * Stage: A10
 * What you need: Units you want to level up, duh.
 * What to do: Kill things. Make sure you keep one shuttle alive so the Generation Break doesn't trigger.
 * PROTIP: If the units are weak or low level, I recommend the pilots you use at least have the Cool-Headed ability maxed out. It will almost always ensure a one hit kill even without tension and thus speed things up tremendously. Other damage boosting abilities, Elite, and XP bonus OP parts help a lot as well.

Appearance Switch Character Abilities
Characters that get to switch their appearance (e.g. Loran Cehack, Schwarz Bruder) also get a few different abilities to choose from when they switch. Even if you switch the appearance back to its original, you'll keep the ability you bought with the other appeareace. So you essentially get to pick from more abilities to make your optimal build compared to the other characters.
 * PROTIP: Sometimes the initial ability is different as well. For example, consider switching to Milliardo Peacecraft when buying Zechs. That way you'll start out with the Cool-Headed ability instead of the (in my opinion) much less useful Chivalry.

Capturing with allied ships
You should know that you also get to keep what you capture with allied ships. When both your warships' capture caches are full or your ships happen to be further away, be sure to send those friendlies to pick them up if you need them.

Using unit collection panel to figure out combination / evolution to the unit
SD Gundam G Generation World has introduced Unit Collection panel to assist players in figuring out how to get a desired unit, if they are possible to be created through some means.

Go to a panel right below the stage selection, which is called unit collection.

Find your unit that you want, and press either O for how to make this unit through a single evolution, or [ ] for combination to make it. It will help you emmensly if you have played the series for some time, or at least Wars, and know how the unit's shadows look like for easier identification.

Now, knowing this, you can back track to whatever unit you have available, or easily obtainable (through capture or exchange or whatever means you have available). The game made it extremely easy for you to collect what you want.