One of the biggest and most pleasant surprises in Leigh Whannell’s second effort as writer/director, Upgrade, is how much it leans on the actual science fiction element of its premise. The basic idea being Grey (Logan Marshall-Green) seeking revenge for the death of his wife, Asha (Melanie Vallejo), after an attack that also left him paralyzed. However, a special device created by a reclusive tech genius, Eron (Harrison Gilbertson), not only gives him the ability to move again, but a built-in A.I. referred to as STEM (Simon Maiden), gives him the ability to do things he never could’ve dreamed of.

The main appeal of Upgrade is undoubtedly its classic B-movie thrills. It’s a gleefully gory throwback to trashy low budget, high concept actioners of the 80s, the kind of stuff you’d see left on the shelf when The Terminator or Robocop was taken at your local video store. And it’s a total blast, especially at how it almost comes off as a surprise. The film spends a good chunk of its first act setting up Grey and Asha, as well as him failing to get used to his new life as a quadriplegic. It feels a bit long, but in a very precise way, to show the slow, excruciating emotional pain he goes through day to day, struggling in his grieving process. But once he gets the chip installed, it becomes a fairly relentless and violent thriller. In a way, it make for a pretty wonderful double feature with The Guest, another great throwback that starts as one kind of movie, and ends in another.

Though, that’s not to say Whannell doesn’t channel his horror roots in this. The gory goodness of the action sequences are incredibly gnarly, and it leaves Grey horrified at what STEM is capable of. However, there’s something more clever at play. The horror isn’t just with the gore, it’s also a riff on classic body horror. It explores the idea of the what happens when you are no longer in control of your body, when you are still inside, conscious, aware, but you’re still powerless. The film explores the psychological toll of that in a way that allows you to have fun with it, but also provides moments where you are left to wallow in the darker implications and consequences of it, and given the application of that concept within a science fiction environment, it gives the movie some real meat on its bones, which I honestly wasn’t expecting.

However, this genre mashup isn’t also without a sense of humor, which is a fairly common element in Leigh Whannell’s work. Though, it’s not just wisecracking or one-liners, the film stages its action sequences in ways that feel like an old fashioned slapstick comedy. This is where Logan Marshall-Green really shines. He’s excellent in the film, but he goes to another level whenever the fighting ensues, and he has to channel his inner Buster Keaton in order to move and contort his body in strange, but calculated ways. It’s really a joy to behold.

Of course, this wouldn’t work if Leigh Whannell wasn’t on top form here. I’ve been a fan of his since his early collaborations with James Wan, and I thought he showed a lot of potential with his directorial debut with Insidious: Chapter 3. Plus, having written the highly underrated dark comedy, The Mule, back in 2014, he shows that his skills aren’t limited to the horror genre. So, him combining sci-fi, action, horror, and comedy (plus, some really solid worldbuilding) seamlessly here is pretty astounding all things considered.

As someone who is generally not a fan of technophobic, “A.I. gone bad” type stories in science fiction, I still had a great time with Upgrade through and through. This is just my kind of stuff. It wears its influences on its sleeve, but still manages to becomes its own thing. It’s a nasty genre picture that is willing to go big, brash, and bold, even to the very end, which delivers one really mean punch. Seriously, mainstream moviegoers are not going to be prepared. The film is a tonally playful rollercoaster ride filled with fun and unique action set-pieces, and a cast that is totally game for it. Logan Marshall-Green is great, but folks like Benedict Hardie and Betty Gabriel take turns stealing the show. Sure, there are some moments where I think the film could have focused more on Grey’s emotional journey, and I think some of the messaging is a tad muddled, but when the ride is this fun and effortlessly engaging, it’s hard not to sit back and enjoy. I had a giant grin on my face for pretty much the entire runtime, and it further solidifies Leigh Whannell as a director worth watching.