Historically accurate. High learning curve but rewarding. (I played with mostly realistic level, there are options for more arcade playing but I encourage you to learn how to work out the torpedo targeting techniques, it's worth it when you succed a hit!) Graphics are great. My 6 year old computer and graphic card struggles at times, but it's definetly playable. Highly recommended for anyone who likes simulators, WWII themed games, or sea-related warfare. It's a must for hard-core subsimmers.
