Web retailing giant Amazon waded into the fiercely competitive set-top box market on Wednesday with the debut of its new “Fire TV” device that provides access to the Amazon video streaming service and to a variety of free and low-cost video games. Priced at $99, Fire TV is the first electronic device to be developed and marketed by Amazon since the company introduced its Kindle Fire tablet computer in 2011. Until Wednesday’s announcement, Amazon had relied on smart TVs and other devices produced by outside manufacturers to distribute its free “Prime” and paid online video content to consumer TV sets. With the introduction of FireTV, Amazon has positioned itself directly against the cable industry and against consumer electronic giants such as Sony, Apple and Microsoft in the battle for the living room. Although competitors such as Google and Roku already offer similar devices at half of the price of FireTV, Amazon hopes to entice consumers to FireTV with enhancements that include voice search functions. In addition to offering access to Amazon’s library of 200,000 movie and TV titles, FireTV also provides connectivity to the content of other online video streaming firms such as Netflix and Hulu. FireTV also includes music streaming capabilities, and users will be able to play thousands of games with the use of a companion controller that retails separately for $39.99. Boasting that FireTV enables his company to leverage its position as a retailer to expand into new fields, Amazon vice president Peter Larson told reporters that, because his company already sells millions of set-top boxes through its website, “we hear what’s working and . . . what’s not working.”