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In page Id Software:

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Commander Keen in Invasion of the Vorticons, a platform game in the style of those for the Nintendo Entertainment System, was one of the first MS-DOS games with smooth horizontal-scrolling. Published by Apogee Software, the title and follow-ups brought id Software success as a shareware developer. It is the series of id Software that designer Tom Hall is most affiliated with.[citation needed] The first Commander Keen trilogy was released on December 14, 1990.