Dynasty Battle: Shin Warriors

Diehard fans of the series will probably be pleased simply because they can take Dynasty Battle with them everywhere, though if you haven't been impressed by the series lately, this simplified handheld installment won't do anything to reel you in.
You'll choose from a large stable of legendary heroes hailing from each of these three factions and then you'll plow your way through one (presumably loose) historical scenario after another as you attempt to unite China under your own banner.
However, Koei rightfully seems to have taken the portable nature of the game into account here by breaking up every big battle into many smaller parts, represented on a tactical map with each node connected to other nodes by varying paths.
Each section of the battle has its own type, from fortress to supply depot to simple open field, giving some areas a greater degree of strategic importance than others. To some extent, you can choose the path you take through the battle by selecting which areas you want to attack next, based on where the enemy's troops are concentrated. However, you can also just plow your way through, without much consideration for strategy, by attacking the next available node.
As in past games, you've got a musou special attack that can be used to clear even more enemies at once, along with a charge move and a ranged bow-and-arrow attack. The basic games is easy to pick up if you haven't played a Shin Warriors game before, and it can be pretty entertaining in short bursts, though not as much over long sessions.
You'll unlock new officers as you play, and there are so many officers with so many mixtures of special attributes that the more interested players will likely spend a lot of time experimenting with new combinations to find what works best.
There are plenty of extra characters to unlock beyond the initially available 15, which, coupled with the many possible officer combinations, makes for a lot of replay value. But that's only if you enjoy the core gameplay enough to replay the game for dozens of hours, and that's a big if.
Good luck!