Its a Visual Novel with super easy short strategy gameplay segements and some minigames
First two games strategy plays similar to Fire Emblem
Third game introduces AP meter which plays like an early Valkyria Chronicles and its becomes a action strategy game from then on
the newest game plays like Dynasty Warriors
What you should remember though is that SW is 100% a Visual Novel
The characters are its focus. You will earn to love these characters and cry. It is Sega's sweet heart series.
Skies of Arcadia? Shinobi? Phantasy Star? Sonic? Yakuza? Streets of Rage? Valkyria Chronicles? Puyo Puyo? Billy Hatcher? NiGHTS?
All the devs from those games have worked on Sakura Wars.
This article puts in retrospect why this series is special