Opus: Echo of Starsong is a visual novel and exploration game from SIGONO, and another entry in their acclaimed series of science-fiction dramas. It follows the exploits of Jun through his memories of a galactic mining rush, time spent with the space witch Eda, and the fortunes and tragedies that visited them throughout life.
Opus is driven by both interactive visual novel elements and exploration, through map exploration, resource hunting, and walk-around puzzles. The multiple levels of interaction mean Opus has a more in-depth gameplay experience than many visual novels, and needing some pointers on where to start is not unexpected.
Making Choices
The choices in the main narrative path are generally about how the characters interact in the moment, along with the potential to earn us resources and memories to unlock. The main plot itself proceeds along one path, and shouldn't cause you to overthink the choice. In the same way, losing your life takes you to your last autosave as Jun, now elderly, clearly recalls that that is not what actually happened.
The choices that occur in the optional explorations are similar, having little impact on how the characters interact. They're more an opportunity to earn rewards and memories, along with shaping how you envision Jun and Eda's histories.
Choices in encounters with pirates and other groups looking to attack rely on the mechanic of either the resilience of your ship (level of armor plating) or your ability to scramble signals. Using the signal scrambler is the potentially riskier option, but may avoid any damage at all. It activates a chance minigame that pits your scrambler's number range against a fixed challenge number. Your scanner then 'rolls' and the higher number wins, meaning you may escape with no collision or cost.
Navigation
On Foot
Navigating walk-around areas often means deviating from a left-to-right path and going up or down ladders — or even backward and forward, deeper into the space. There will always be something in the caves that points directly to what to do next.
If stuck, remember that progress could rely on an interaction with a door, a lumen seal, a ladder, or a cliff. It's important to use Jun's curiosity for objects as you walk around.
Flying Ship
On the galactic map, navigate by moving your pointer to a location and placing it directly over that spot to see if you can reach it in one move, or whether you will need a pitstop. You will also need a decoded signal and range to travel there, and so cannot just free fly.
You will need a full tank in order to make some journeys and allow full exploration, so it's advisable to always fill up on fuel at any trading post.
Exploration And Collecting
On Foot
Look out for interaction points that pop up as a dot in a white circle while walking around. These are not only interactive elements, but also might lead to memories to collect, such as the many ancient seals you encounter within caves.
Keep an eye out for blue plants once you get the eco scanner, which makes lumen plants available to collect when exploring. Make sure to pick some up, as they can sell for a good price, are needed in certain interactions, and unlock memories as you find more.
Flying Ship
Heading to spots between coordinate checkpoints allows you to find things like spare ship parts to use in upgrades, as well as ship fuel and money. It's wise to use the exploration kits that you collect and buy. These stops will also sometimes be necessary, as your target may be outside your range.
If you encounter interactions that require items you don't have, you'll be able to return later with those materials found during exploration.
Upgrades
In general, you should seek to upgrade as early as possible. This way you will be able to upgrade your signal modifier power early on. This makes it much harder to crack, and more likely that you will be able to pass through areas undetected.
Being able to upgrade early is reliant on exploring areas between checkpoints, as well as the optional areas indicated at checkpoints often, to collect the specific materials needed. Note that the game does limit the discovery of some upgrade items to later areas. so you're unlikely to find those crucial specialized pieces early on.
Upgrading ship armor relies on having some damaged armor in your inventory, so it might be worth getting hit if you can't find any during exploration.
Using Starsongs
In order to open a door with a starsong, you need to match the length and spread of the song's peaks to the pattern on the door, and then resonate.
When it comes to incomplete starsong gates, transmutation chambers align the resonance lines with the symbols present on the gate, as if the full image was there.
To resonate with the ship's coordinator, make sure the one, correct starsong element is centered when Eda sings on the bridge, by listening for the similarity as you bring each element close to the center.
Some gates require two songs, and you will need to pick the ones relevant to the areas of the seal. If you haven't already done so, you will likely need to collect one from the specific cave featuring the multi-song gate.