According to Mass Effect 2 Prima Official Game Guide [1]Browne Catherine (January 2010). “Training”. Mass Effect 2: Prima Official Game Guide. Roseville, California: Prima Games. pp. 8–33. ISBN 978-03074-6706-5., Mass Effect 2 is a single-player action role-playing game in which the player takes the role of Commander Shepard from a third-person perspective. Shepard’s gender, appearance, military background, combat-training, and first name are determined by the player before the game begins.
According to HowLongToBeat.com[2]https://howlongtobeat.com/game.php?id=5699, it takes an average of 24 and a half hours to beat the main story line, and 35 and a half hours to beat the main story line with the extras.
The speedrun record of Mas Effect 2 (submitted on 02-23-2021) is 1 hour 11 minutes and 1 sec.