1914 Shells of Fury is a submarine simulation set during World War I. The game centers on commanding Kaiserliche Marine U-boats from the beginning of the War in 1914 to its end. It was developed by h2f Informationssysteme and Rondomedia and published by Strategy First in 2007.
Source: Wikipedia, "1914 Shells of Fury", available under the CC-BY-SA License.
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The game features 4 campaigns covering the whole or part of the First World War. Besides that, there are a number of single player missions and an editor to cerate new ones