Overview
Forgotten Coast is a blockout for a singleplayer action adventure game, set in the ruins of a Celtic settlement (or “castro”) and an adjacent island Hermitage. It was made in Unreal Engine 4, and is designed in the style of games like Uncharted or Tomb Raider.

Goals
The primary goal was to do some “meat and potatoes” action adventure level design. This meant a heavy focus on composition, while leaving room for light combat encounters and simple gating puzzles. As with similar games, there also needed to be room for narrative beats and dialogue.
Theme
I wanted the player to get a sense of lost and layered history. Here, pagan ruins face an abandoned medieval church. Atmospherically, I wanted a sunny, coastal feeling, even as things go wrong – like a day out at a tourist destination has gone badly.
Research and planning

There were two big inspirations: the islet of Gaztelugatxe in Basque Country, and the Castro of Santa Tegra in Galicia. I collected reference photos and read up on the locations. I’ve visited these places in the past, so they are personal inspirations.
I sketched rough plans on paper and experimented with shapes for the island. I decided the Celtic ruins should naturally flow down a hillside in some way. Then I opened Unreal Engine to begin laying out the terrain. I also installed the Advanced Locomotion System by LongmireLocomotion, a popular set of Blueprints that would provide an Uncharted-style character controller.
Blockout

The first rough blockouts were pure BSP with large primitives. The player’s path was the most important thing to consider during this stage, as I wanted moments of strong composition in which an interesting vista could be framed, such as in the exit doorway of the hilltop hut.


Eventually, I started to introduce static meshes to fill out other shapes, and fill the boundaries of the map, with some classic green rocks masquerading as placeholder trees, for instance.


Since I also wanted combat in this level, the ruined stone foundations of the Castro were the perfect candidate for cover. In this area, the player would be tasked with getting a key item (some coal) from a nearby stone circle, familiarizing them with the layout of the ruins before the first combat encounter begins.


Once the geometry was more or less defined, I began working with Blueprints to implement puzzles, key items, moving platforms, doors, enemies, secret items, a basic dialogue window, etc. The two pictures above show the beginning of blocking out, and a near-final version.
Iterating
There were many tweaks, big and small, as I went, but I’ll focus on three things.
Adding caves

The map was an open and sunny space but it lacked variety. Almost everything was happening outside. To create a sense of tightening and widening space, I added caverns to two areas: one under the Castro, and another mid-way up the rocky island.
The first cavern gently introduces the “keywheels” the player will be using to power platforms and open doors. The second cavern is a straightforward combat encounter space, with a raised walkway where enemies can get the drop on the player.
Moving platforms as “valves”

There is a platform that divides the Castro and Hermitage. This was designed to rise, allowing the player to jump the gap, after using the required “keywheel” to power the platform. The platform would return to its original position, acting as a valve.
But this presented problems. The player would have to rely on sound alone to know the platform is rising (since it is out of sight by default), and the timing of their jump would need to be rushed. If the player misses the window to jump and stays on the platform, they are slowly lowered into the sea and are unable to escape.
Since this wasn’t intended to be a challenging moment, I decided to place the platform high as default, and cause the “keywheel” to lower the platform instead. This puts less pressure on the player’s attention and ability. Crucially, the platform cannot now trap the player.

It’s still quite inelegant in its current form. But at this stage I was happy to keep things simple and move on.
Narrative beats
During iteration, a friend suggested that a fire started by the player (part of a puzzle) should still be producing smoke from the chimney of the hut when you see it later, from afar.

I implemented this, but I wanted to go a step further and in the end I made the fire a small but ongoing narrative element. The player now sees smoke billowing from the hut at one point. And near the level’s end, they mount the rooftop of the hermitage to see that the fire they started has spread out of control, incinerating a precious monument of ancient history… oops.
Secrets

To encourage exploration and reward curious players there are three secret “trinkets” to discover. The first is in a ruined foundation in the Castro, easily discoverable. The second requires a well-timed jump. And the third is tucked away behind the hermitage. A broken, non-interactive trinket is on the path at the very start of the level to signal there are such secrets to find.
Final design
Once I was satisfied with the flow and all elements that required Blueprints, I did another pass on the geometry, colour-coding surfaces and generally refining the level’s appearance to help define the artistic requirements that might be involved. At this point the environment began to feel far more cohesive.
There’s lots of room for improvement. Combat spaces could be more interesting. Pacing could be better. If I were to do it again, I’d focus on a more dramatic or rounded ending. I might have expanded the Crypt interior significantly, adding a final (more challenging) “keywheel” puzzle. An escape sequence of some kind, with a final combat encounter, may also have rounded things off nicely. As it stands, the third act of the level ends quite abruptly. Never mind!
Below is a longer playthrough of the entire level.