Instead of being lost in a sea of similar 16-bit shooters, the folks at Dennaton Games (Miami's developer) set themselves apart by planning very carefully for their player's inevitable death(s). Most loads are instantaneous, levels are typically only about a minute or two long, (on a successful run) and the information gained with each attempt will help you get a bit further next time.
Despite the short levels you should be ready to take full advantage of the quick restarts. Environments are jam-packed with enemies to be brutally murdered, but one mistake and they'll gladly return the favor. Though there is little room for error, the tight controls and solid level design make Miami's challenges feel surmountable and enjoyable.
While Hotline Miami is all about learning from failure it's most certainly not just a set of levels to be memorized. The game has a degree of randomness to it, and it's this unpredictability that makes completing each level feel so rewarding. A guard might decide to open a door they had previously walked by, or you might find that the shotgun you picked up last time is now a baseball bat. This uncertainty prevents the frequent restarts from feeling stale or repetitive.
Miami feels highly controllable, but also unpredictable; it is challenging without being aggravating. The aesthetic and narrative styles are wonderfully absurd and self aware, while the overall presentation is spot-on. Dennaton Games have done more than enough to earn their $10 asking price, and if you have even a passing interest in retro action games you'll find much to enjoy in Hotline Miami.
Edit: I should mention that I play this with a 360 gamepad, not a mouse and keyboard. When I praise the game's control scheme keep that in mind.