From Before I Play
- When you escape from a certain enemy hideout and get spat out into a tiny forest screen, go far left and far right for very good, hidden treasures before you leave. One of the library books you can collect for your ship allude to checking these out on NewGame+ if you missed them originally, since you can't go back here once you leave.
- Fight bosses, even optional ones. Those little tokens you get for killing each boss can be used at the end of game to trade up for amazing equipment and stat-ups.
- Save allies. If you see a soldier fighting an enemy during a plot event, rescue him. A soldier in the island base gives you rewards based on how many allies you save, which carries through to NewGame+.
- Use all your SpeedUps and StrengthUps on Sammy. At the end game, Sammy turns out to be the best of the fighters simply due to the fact that he attacks twice. Even though his attack is lower than the other fighters due to this, raise his Strength high enough and he can hit 2 9,999's per turn.
- Haste stacks. Up to four times, I believe. Try casting it 4 times on your best fighter and watch him fly. On the same note, Slow and Might stack as well I believe. If a boss is giving you a hard time just Slow x4 it.
- Open every chest you see. It might contain a jewel you can use to open a summon's temple.
- Selling hunted meat is a good way to get a lot of early-game gold. Most characters have their own unique hunting method on that note, but sword (Glenn) seems best.
- The stuff you can get from completed puzzle chests is really, really good usually. Also, the contents are randomized upon opening, so what you got in one playthrough might be different later, but it's not unique equipment.
- Every single character has unique dialogue if you bring them along for plot events, adding to replayability. Some characters have extra bonuses if you bring them along with you if the area relates to them. For example, Justin makes arrows appear that show the shortest route to the switches if you take him to his castle as it burns .
- Mind your choices when speaking to Meredith or Vixen. You can be as big of a dick or as nice as you want to either of them, but which one you were nicest / less of a dick to slightly modifies the ending and how they treat you through the course of the game.