Sadistic to a fault. The series list is balanced excellently, it sounds and looks great, the animations are top notch, the interactions between the series characters are humorous and well-written... but the game itself will pummel you mercilessly if you haven't optimized your sortie group and support attack tactics. The enemies have comically inflated health and dodge rates, and the last ten or so stages slowly grow ridiculous.
Still an easy recommendation if you like the series list, however. Lots of strong work in the presentation department.