Although Mr. Shifty is clearly inspired by Hotline Miami, it sets itself apart with the speed of the gameplay and the focus on quick reflex action. The Nintendo Switch version has some bugs as at launch, and the game can be beaten in just a few hours, but the fun and addictive experience makes this a worthy addition to your Switch library.
The Specter of Torment expansion really added to the game series with a better story and more fluid gameplay. Its not particularly long, but the fun, challenging, old-school platforming makes this a game worth playing. I would recommend buying the Treasure Trove edition with the original game and the two expansions and playing them in the order of release. It's a great package and Specter of Torment is the strongest of the set.