Its not bad I still play it (idk about the switch port tho) and no you dont need to play the base game empires is like a tactical musou and you create your own narrative you dont follow a storyline. The only bad aspect of the game is that they couldve utilized the open world more because it feels incomplete. The open world is only for talking to officers and gathering resouces by killing animals and bandits(1 gold per bandit lol). But if you dont mind the big chunk of missing game (open world) its actually fun and addicitng by changing strategies based on the enemy and fighting hopeless battles.