Unlike the highly realistic 'Aces of the Deep' 'Das Boot' takes more emphasis on action elements then on tactical planning. This becomes obvious in several aspects which are discussed later. Graphics are quite ok for 1990 whereas the sound is minimalistic.
At the start you can choose whether you want to practice several situations or play a scenario. In practice you can improve your skills in defending against air attacks, avoiding surfaced or submerged (yes, you read that right! You can manouver your ship submerged from an outside view!) minefields, firing torpedos etc. When you think you're good enough you can try one of five scenarios.
But first you select one of three difficulty leves and which Type VII submarine you want to command: an aged VIIA, a VIIB or a modern VIIC (well, I couldn't make out any big differences between those three...) To serve those people who expect a certain degree of realism from a simulation (are there any??) you can decide whether torpedos can fail to detonate, damage can be repaired on sea and your equipment is from before 1941 or after 1941 (mainly affects available torpedo types). The five scenarios take place in different locations, from Norwegian fjords to the Arctic Sea or the North Atlantic. In each scenario you have to accomplish a pre-set objective - no random elements here, so no longlasting playing fun to be expected. The objectives range from sinking certain ships to bombarding land-based gun emplacements or getting through the street of Gibraltar and even dueling an enemy sub. Sounds like lot of fun but as said before, when you have played each map once or twice you know what you can expect.
After a short briefing you find yourself on the map. It is parted into 4x4 squares and not very big. So you patrol around and take a look at the various stations. You can view your boat from two external points, an overview and an underview (when submerged you can evade mines there). You can also take control of the deck gun (astonishing 4 rounds per second!) and the anti-aircraft guns. The radio room is the most innovative part of the game. Incoming messages are encoded and you must first find out which way to decode it. You can even decipher enemy messages by manually switching the decoding key wheels (err, hard to explain but you'll see when you try it). Thus you can get some valuable information about enemy whereabouts. In the control room you can control your most important steering options like speed, diving rate and rudder. In the torpedo room you can select which torpedo to load into the tubes. There are three different types of torpedos: magnetic, acoustic and looping, but their differences aren't too big. Zoomable binoculars help you identifying unknown ships.
When you have detected a ship you should simply drive straight to it. When it turns at you and fires, you should dive and fire some torpedos from periscope depth at close range. But you have to aim your weapons by eyesight - who needs such technical gimmicks like torpedo data computers anyway? When it doesn't fire, it's a neutral ship. Sometimes you're attacked by planes which you can easily shoot down with your AA-guns.
Well, that's basically all that can be told about this game. It's fun for some minutes but not more as there are no random elements in it. If you want to play a realistic simulation of submarine warfare, stick to 'Aces of the Deep' or 'Silent Hunter' instead.