What do you think when you receive a call from an unknown number?

My first thought is that it’s bound to be a sales representative trying to sell something I don’t need, an advisor who wants to help me with a car accident I didn’t have, or the bank trying to tell me to take out a loan at an extortionate cost. I usually don’t bother answering and figure they’ll leave a voicemail if it’s urgent.

But what if the person on the other end of the line was someone who had misdialled your number, and really needed your support despite you not being their intended recipient? And what if answering their call could save the world and change your life? This is the premise behind Unknown Number, the first entry in a new ‘first-person talker’ genre created by developer Godolphin Games.

The title has been on my wishlist since having the opportunity to play the demo during the Steam Next Fest in June. I enjoyed its quirky vibe which felt similar to Blind Drive, and its central gameplay mechanic intrigued me: players had to use their voice to converse, navigate, solve puzzles and even impersonate other characters. My thanks go to Benjamin from Plan of Attack for sending over a review key so I could experience the game in full.

You’re dragged into the story after receiving a call from two eco-warriors named Ethan and Amanda. They’re on an abandoned oil rig in the middle of the North Sea, attempting to steal seven-billion dollars from a petrochemical company called SLIGOIL. You might not be the person they meant to contact but now they really need your help breaking into seven vaults. Can you get to the bottom of what’s going on and find out who’s pulling the strings, or are you just an unwitting pawn in somebody’s scheme?

Over the course of around three hours, you’ll receive voicemails and calls from unknown numbers through an in-game mobile device. The callers will occasionally ask questions which can usually be answered with a simple yes or no spoken into your physical microphone, although sometimes you’ll have to be a little more detailed or even creative. You’ll see spikes appear on a sound-bar displayed on the screen as the title registers your responses before the characters react accordingly.

This is brilliant when it works well. It almost feels as though you’re having a real telephone conversation and the effect is one which pulls the player into the narrative. But when it doesn’t, it can temporarily push you out of Unknown Number’s world. For example: when Ethan asked a question and I took too long to answer, the game continued as though it had assumed I’d provided the correct response. There were also occasional moments where it seemed to mistake ‘yes’ for ‘no’ and vice-versa.

I should point out here that this wasn’t entirely the title’s fault, however. I initially started playing using the in-built microphone on my laptop as it would allow Pete to follow along but this really wasn’t the best idea. The game was able to pick up Zelda meowing in the background as well as other ambient noise and it affected the outcome of my answers. These problems reduced once I’d grabbed my headset, so I’d definitely recommend playing with a dedicated microphone in a quiet room.

The puzzles encountered aren’t particularly difficult but the fact you’re solving them using your voice puts a fresh spin on challenges. I’m a little disappointed we didn’t play on stream because it would have been hilarious! The title had me singing nursery rhymes, swearing allegiance to a mysterious group run by kids, and talking in a high-pitched voice to impersonate an executive and break into a conference call. Actually, scrap what I said – it’s probably for the best that nobody else saw me doing these things.

If help is required, an assistant reminiscent of Clippy called Detective Vox is available through the in-game mobile device for hints. I doubt most players will need this support based on the level of challenge, but it was nice seeing him occasionally pop up whenever he thought I might be stuck. Clear clues are provided throughout the title on how to open each vault and I’m pleased to report that all the solutions are logical, so you won’t be left scratching your head in frustration.

Most of the action takes place through the mobile device and that’s what you’ll be focusing on. While there are some background images, these exist to add to the atmosphere rather than show gameplay visuals. This allows the story to play out fully in your head as it would if you were speaking on the telephone to a friend. It’s thanks to the great cast of voice-actors that this works as well as it does, with excellent performances from Candice Palladino and Simon Snashell in their roles of Amanda and Ethan.

There are some nice touches which wonderfully add to the urgency of the characters’ situation, making your stress-levels rise despite being unable to see what’s going on. For example, your ring-tone sounds normal at the start but gets louder and more intense the further you progress. You’ll also receive voicemails from the Metropolitan Police who are hot on your tail and may even use some of your responses against you. These sections provide some light comic relief with their humorous introduction messages.

Unknown Number includes a few augmented reality (AR) elements too. At certain points, you’ll have to use a browser window to trawl through the SLIGOIL website for information that could be used to your advantage. There’s a danger of giving away too much and spoiling the surprise so I don’t want to overshare. But what I will say is that there’s a great part towards the end of the game where you’ll need to do something outside of it to progress and this was one of the highlights for me.

I mentioned above that the vibe is similar to that of Blind Drive. While Unknown Number is more serious in its narrative, you’ll still find yourself laughing at the eco-warrior’s antics or police’s recorded messages. There’s also a section that’s rather tough to get through emotionally. You know exactly what you need to do and it’s only your voice which can give the order, but you’ll battle with yourself about whether to go through with it. The Steam page doesn’t say anything about multiple endings although it does mention decisions which impact the story.

I would have loved to have experienced this game on a real mobile device as this would have added brilliantly to the effect. It would have been cool if you received the calls periodically throughout the day and never knew when they were going to come. As it is, you don’t have to wait too long for the next one or for a voicemail to appear in your inbox. The good thing is that you don’t have to answer them immediately if you want to step aside for a moment to make another cup of tea.

Unknown Number is a fun release full of both drama and humour, with a lovely message at its conclusion which you’ll just have to see for yourself. When it works, it really feels as though you’re part of Ethan and Amanda’s adventure; and while there are a few little niggles, most can be solved with the use of a headset and don’t spoil the overall enjoyment. It’s likely a lot of players won’t have any trouble with solving its puzzles as the difficulty level isn’t very high, but the way you complete them is unique and creates a very immersive experience.

After my time with the game, I’d definitely be interested in playing more first-person talkers. Hopefully Godolphin Games have started a trend and we’ll see a few more very soon.