This game had some potential but it becomes boring due to its story and a lack of difficulty. The story is a cliché-fest done poorly. It's completely forgettable as the amnesiac male lead, Aldo. I briefly played the female lead, Reiha though, but I think it's more of a different perspective, but Reiha is in your party if you start with Aldo as the lead though. Basically you have to take out some bad monsters (corrupted spirits) and the characters talk more in the style of observations rather than have interesting personalities. I do find it funny how the characters talk about dangerous areas when I can easily breeze through this game without even trying. In other words, the game lies to you when it's not boring you to death. I wish I could summon a better game to play than this. I thought the character designs were generic but at least the field art was ok and the special moves looked pretty good. The sound is nothing special.
The game's bosses are braindead easy. I was rescued by this guy from a boss that was so easy (3rd boss) that I did not get hit once and he (my rescuer) only lost 1/5th his HP. The thing is this game plays as a real time strategy game, which makes it worse since you cannot really dodge attacks in this type of gameplay. The attacks, however and the AI, are really good and useful. The AI will back you up and will not do idiotic things like get stuck in walls nor kill themselves by running into "friendly" firewalls like in LostMagic. I just want to say at least the gameplay is different since you do use the touch stylus and either tap enemies or use straight lines for special moves which look pretty cool by how much faster you move.
The different weapons don't really mean much either; the sword is most accurate but the axe and spear do slightly more damage but are less accurate and feel a little slower. At least the interface is nice, letting you use up to 10 items/skills/weapons quickly by tapping on it rather than go through some long menus. Lastly, you can forge weapons, but this isn't really that big a deal since the game is so easy that it does not matter. At least the fights are faster and the skill learning intuitive (like in a lot of games where you level up and invest skill points in abilities).
I am glad though that the battle system in Summon Night: Twin Age is a lot better than the Game Boy Advance game, Summon Night: Swordcraft Story which badly ripped off Tales of Destiny with its 2d battle system that lacked any special moves (you had boring spells that boosted/changed stats and a summon in addition to only 1 character in your party for the game). The encounter rate was very high in the dungeon crawler, which compounds this dull combat, and I felt slow weapons like the spear are useless. The dialogue in Summon Night: Swordcraft Story was good but unfortunately, it let me down for Twin Age to be dull. Swordcraft Story's basically had you fight in an arena, forge, and make some interesting choices like easy money by selling your swords you forged which ruins your reputation because the guy bought it off you when you were a novice and claimed it was the town's best.
Summon Night: Twin Age would have been a good game if they made the bosses a challenge. A strategy-free strategy game is a joke. For some later bosses, just hold off until the barrier is down and repeat those special moves ad infinitum. Getting to the bosses by abusing the same moves on regular enemies who were just as boring to fight was dull too.