Hotline Miami 1- This game is very difficult on your first run (especially the boss fights) but when you get the hang of it, it's incredibly satisfying. Its story is well written and the levels (aside from Trauma, which totally sucks) are all fun and allow for several playstyles. Wanna beat them all to death with a bat? Go ahead. Run-and-gun? Yep, you can. Drill a hole into mobster's heads with the Carl mask? You can do that too. Unfortunately this trait of letting you kill people any way you want to isn't shared by its prequel/sequel Hotline Miami 2: Wrong Number.
Hotline Miami 2 - Although it has a great story and some interesting new mechanics, Wrong Number's levels are often times ruined by far away, gun-wielding enemies who shoot you before you even see them, forcing you to use guns constantly and play a very certain way every level in order to progress. The Beard levels were particularly hard in my experience and if you don't want to constantly die from getting shot by someone on the other side of the level over and over just stick to Hotline Miami 1. If it were just HM2 I'd give it a 3/5 but HM1 more than makes up for its comparatively mediocre sequel with its well-designed levels that provide a sense of hurried, speedy improvisation with melee, guns and stealth. At least the sequel's soundtrack is still badass.