Oh boy, this was a movie that had an idea and just ran with it. Luckily, Radcliffe was up to the task of both the physical comedy that entails when you, y'know, have guns bolted to your hands, and just fully committing to the bit. Honestly, he's great throughout and really takes the film up a notch. None of the rest of the cast are quite as memorable, though they all play their roles perfectly well, and the plot itself is well-paced, with plenty of unexpected twists and turns. I wasn't entirely sure about the whole cop-father, murderer-daughter, blood-duty angle, nor the sudden twist killing of said cop-father, but when taken in totality with the rest of the plot, I think it kinda works. You certainly get a decent chunk of character development out of it, and it makes the inevitable team-up actually make sense, beyond simply having a wild child character go a bit soft.
I could have personally done without the love-interest angle. Early in the film it was used well, and the script clearly had a point to make about Hollywood romances and the reality of violence, but I'm not sure it was actually necessary. I think her character could have just exited stage left around midway and it would have been fine. Similarly, the fate of the Nerf friend at work just felt a little excessive (which is saying something for a film like this) and more like they wrote his kidnapping and then forgot about it, so just offed him to tie up a loose end. Again, it could have just been cut. In some ways, the whole girlfriend switcheroo routine would have been more in keeping with the dark humour if it had just been a random henchman under the cloth with their head blown open.
Still, somehow Guns Akimbo makes an idea that should have probably never left the toke circle into an entertaining, visually interesting movie. It does get a little lost in trying every possible effect known to mankind, with Mortal Kombat style fatalities, all manner of POV shots, drone work, pan zooms, Scott Pilgrim style jank zooms, the lot, which means that it's definitely got a strong aesthetic, but it never quite settles on what that aesthetic should be. That definitely feels a little amateur; Tarantino this ain't. But it's also a lot of fun and, ultimately, what more do you want from a story like this?