Passage: Upon release, Episode One was sold in both retail stores and Valve's online Steam distribution system, where it was sold at a discount price. The game was also distributed by Electronic Arts as both a standalone release and as part of Half-Life 2: Platinum Collection. It was available for pre-load and pre-purchase through Steam on May 1, 2006, with Half-Life Deathmatch: Source and Half-Life 2: Deathmatch immediately available for play as part of the package. Episode One is available as part of a bundle package known as The Orange Box, which also includes Half-Life 2, Episode Two, Team Fortress 2, and Portal; and is available for Mac, PC, Xbox 360, and PlayStation 3. About 1.4 million retail copies of Episode One were sold by 2008.Response to Episode One was generally positive, and reviewers praised the game for having more intricate, well-paced gameplay than Half-Life 2. The game's interactivity, particularly in the form of Alyx and her reactions to the player's actions and the events of the game, was also singled out for praise. PC Gamer commented that "while this inaugural episode may not be the essential FPS that Half-Life 2 is, I can't imagine any shooter fan who'd want to miss it." In its review, PC Gamer UK directed particular praise to the balance between puzzle-oriented and action-oriented challenges throughout the game. In Australia, the magazine PC PowerPlay awarded the game 10 out of 10. Edge praised the "deftness" with which the game was able to direct the player's eyes, and the strength of Alyx as a companion, concluding, "In an interactive genre bound to the traditions of the pop-up gun and invisible hero, it simply doesn't get more sophisticated than this."  Episode One earned a scores of 87/100 and 85.59% on review aggregators Metacritic and GameRankings respectively. IGN awarded Episode One "Best PC FPS of 2006" and described it as a "great bang for the buck using Valve's new episodic plan", although it did not offer "the complete experience that Half-Life 2 was". GameSpy ranked Episode One...

Question: How any hours did Episode One take to complete?
4–6