What does the 1930s sound like? Interview with Damian Czajka from MOUSE: P.I. For Hire Team

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MOUSE: P.I. For Hire is a title that took the indie gaming scene by storm and quickly broke into the mainstream. One of the main reasons this first-person boomer shooter from Fumi Games has gained popularity is its unique style, which features hand-drawn rubber hose animation inspired by 1930s cartoons, as well as an original jazz soundtrack accompanied by immersive special effects. At this year’s Digital Dragons Conference, we had the opportunity to speak with Damian Czajka, a sound designer and composer who worked on audio direction for this game. 

As the audio lead at Fumi Games, what exactly were you responsible for during the production of MOUSE: P.I. For Hire? 

I handled both the SFX and the musical direction for the game. Together with the composer, we determined which type of music would work best at each stage of the gameplay. As for the SFX, Łukasz Kościelny and I were responsible for all the sounds generated by the main character, objects, and the environment. Every single sound that isn’t music falls under the category of SFX, but some musical elements can also belong to it. These include, for example, various special effects used to exaggerate or emphasize specific moments in the game.

We’re talking about a game styled after 1930s animations – how do you capture that atmosphere through sound?

First of all, we had reference material consisting of animated films from the 1920s and 1930s, such as Popeye the Sailor, which represented the rubber hose animation style we wanted to recreate. So, in the audio department, we tried to absorb as many details as possible from those animations, and we noticed that the sound drove the narrative there: whenever something happened on screen, various effects were used to draw the viewer’s attention. 

Those effects often required a tremendous amount of work, involving orchestras, specific props, and sometimes even custom-built machines to create the desired sounds. That is why the immense effort put into creating such sound design meant that the music and its accompanying effects came to the forefront.

We wanted to recreate that atmosphere in our game, but we had to do so carefully, because if every sound was treated as a main character, the player would eventually become overwhelmed. We had to decide which sounds would serve as background noise and which would signal plot twists, new locations, or new items.

The next step was processing the audio through a simulated vinyl record effect by reducing both high and low frequencies and adding subtle saturation. This created the warmth of an old record, preventing the sounds from feeling too modern.

You also gave players the option to choose from different sound degradation settings: vinyl records, cellulose discs, and two types of phonograph cylinders.

Yes, that was the next stage of our work. However, we kept in mind that most people playing a boomer shooter want to clearly hear everything happening around them, so the default experience features no sound filtering at all. But if someone wants to feel as though they’ve traveled back to the 1920s or 1930s, they have that option. 

It’s still somewhat of a fantasy version of old audio, because if we truly returned to the earliest phonographs with aluminum foil cylinders, a game simply wouldn’t be playable with that level of sound quality. We pushed the sound degradation as far as we reasonably could, simulating progressively older media all the way back to black and brown wax cylinders.

You mentioned avoiding overstimulation – so how did you balance immersion and audio design?

This is where the final stage came in: direction. We had the game, the mechanics, and the story told through the levels, but now we had to communicate all of that through music, sound effects, and voiceovers. For example, there’s an asylum in the game featuring machines that extract ink from characters. The distinctive sounds of those machines were created using the sound of someone slurping through a straw.

On one hand, it helped establish the atmosphere of the location and mark the transition into a new area; on the other hand, it conveyed that the patients were already at their wits’ end. A sound that would normally be humorous or annoying instead created a feeling of isolation and unease.

And how did those distinctive sounds work together with the music to tell the story?

I’ve known Patryk Scelina, the composer of the Mouse soundtrack, for 15 years now, so on many issues we understood each other without words. Together, we planned the dynamic and calmer moments, the sounds in the foreground, as well as the pauses – because music resonates even when it isn’t playing. Sometimes we even created soundtracks for levels that hadn’t been built yet, but we knew where the action would take place. 

For example, we knew there would be a Wild West level featuring duels, bandits, sheriffs, underground tunnels, and gangs illegally producing cheese. That immediately suggested what instruments and style we should use. In that case, we drew inspiration from the famous piece The Entertainer, performed on an old, out-of-tune honky-tonk piano.

So, Patryk developed music systems containing detective and action themes, tracks for smaller and larger arenas, and boss battle music, while my job as music director was to juggle all of that. Our goal was for every level to feel like an episode of an animated cartoon, and that’s the effect we aimed to achieve.

In terms of presentation, Mouse is often compared to Cuphead. How do you feel about those comparisons?

They mainly stem from the fact that Cuphead embraced the rubber hose animation style earlier, but in terms of gameplay, it’s a completely different game from ours. Cuphead is a challenging 2D platform shooter, whereas our game is a 3D first-person shooter. Of course, Cuphead was another source of inspiration for us, but from the very beginning we wanted to develop our own style so that the mice, rats, and shrews in our game wouldn’t simply be copies of characters from Disney movies. 

And what was your reaction to the game’s enormous popularity? Did you expect such a reception from players?

I joined Fumi when the first demo had already been created and a video had been posted on social media. It gathered millions of views in a very short time, which was a huge shock for the entire team. It also showed us that people were interested in a style that, despite being nearly a century old, still felt fresh.

For many young players, this was their first exposure to this type of animation, which I think is particularly important because our game, in a way, preserves an interesting chapter in the history of animation for future generations. Even back then, we had the feeling that we were doing something with enormous potential.

The distinctive visual style of Mouse also helped it stand out from many other titles immediately. I didn’t expect such an explosion in popularity, but I was quietly hoping for it. It was truly heartening for us that once we released the game and started receiving feedback, players began sending us drawings, their own animations, as well as positive comments about music and animation. Many people wrote that the hand-drawn visual style had sparked their imagination, so we’re very grateful that we had the opportunity to create a game that had such an impact on the community.