Essentially, Jammy is a MIDI controller with built-in sounds. It’s not the first guitar-style MIDI controller, but they’re not common. There’s a good reason for that: They’re very hard to do right. There are a lot of moving parts, and the way in which a guitar is played makes it much harder to track and translate into machine-friendly data than, say, a keyboard. And it seems like the team at Jammy ran into a lot of the same problems that everyone else has had over the years, from Casio to Roland to Jamstik.

The tracking on Jammy and its ilk just isn’t good enough to satisfy the kind of person who can’t leave their guitar at home. Strum a few open chords or pick out a simple, midtempo melody and you might not have much of an issue. But the moment you start trying to incorporate slides, bends, hammer-ons or pull-offs or play anything faster than, say, 120 bpm, you’re going to run into trouble.

My Jammy sometimes fails to detect my picking, especially on the low E string. Even when it does initially register a note, occasionally it abruptly cuts off, leaving nothing but uncomfortable silence in its wake. I was able to improve things by diving into the settings and changing the muting sensitivity. But part of the issue is that guitar-style MIDI controllers are not very forgiving. Tiny imperfections in your playing might go unnoticed on a real guitar, but here they become showstopping problems as notes fail to ring out or the wrong ones come through loud and clear.

This is made all the more problematic by the fact that Jammy just doesn’t sound natural. It’s essentially playing back samples, which creates this weird gated effect, especially on the electric guitar sound. There’s an audible background hum when notes are playing that simply vanishes when they stop ringing out. And if you bend a note, the digital pitch-bending effect is so harsh and unmusical that it’s almost comical. It ends up sounding less like a real guitar and more like a mid ’90s robot impersonating a guitar.

But let’s take a moment to acknowledge that some of what Jammy has accomplished is legitimately impressive from a technological standpoint. That this thing can register hammer-ons, pull-offs and bends at all is pretty cool (even if it doesn’t do so reliably). It can sense palm muting too, for when you want to get your metal chug on. And the latency is impressively low; when you pluck a note, it sounds immediately, with little to no perceptible delay. This is something I’ve heard complaints about with the Jamstik, though having never played one myself, I can’t confirm how serious of an issue it is.

Unfortunately, its being technologically impressive doesn’t actually mean it’s enjoyable to play. And you’re only going to make things worse if you try to use the app’s built-in effects “pedals.” They sound… rough. They’re cold and digital, and not in an enjoyable way. The distortion in particular is thin and sounds more like a bit crusher than the Boss Metal Zone its graphics are based on.

Even the areas where Jammy more or less succeeds come with caveats.