INKURSION dev shares how it got Unity 6 HDRP running at 60fps on Steam Deck

The developers of INKURSION, a narrative platformer made in Unity 6 HDRP, say they reached a stable 60fps on low-end hardware, including Steam Deck, without losing the game's bioluminescent look. The account comes from a post by the studio, 19HzStudios, on r/Unity3D. It is a developer's own report, not an independent benchmark, and the post gives no frame time figures.

The mirrors saw the biggest gain. The game uses HDRP planar reflection probes so players can see their octopus character, and rendering them every frame was costly. Now a mirror renders in realtime only when it is on screen and the player is within a set radius. Even then it captures a snapshot at an interval rather than every frame. The team says this still looks smooth enough that the eye doesn't notice, and calls it one of its single biggest FPS wins.

The octopus has eight fully physics-driven legs, which means many rigidbodies and joints plus procedural walking scripts for step reach. The team tuned joint counts per tentacle, simplified collider shapes, adjusted solver iterations, and made sure segments sleep when idle. The aim was to keep the floppy, reactive feel without the physics step eating the frame.

On the rendering side, the team cleaned up and LOD'd environment meshes, cut shader variants, and simplified its heaviest shaders so lighting reads the same at lower GPU cost. The game has a lot of foliage and repeated props, so batching mattered. The developers say cutting draw calls freed more CPU headroom than almost anything else.

For upscaling, the game uses DLSS on NVIDIA hardware, which lets low-end RTX cards render at a lower internal resolution. On Steam Deck it uses FSR, since DLSS is NVIDIA-only. If you are pushing HDRP toward handhelds, the mirror throttling and draw call reduction are the techniques worth testing first. The studio offers more detail on the ragdoll and mirror setup in the thread, and a demo is on Steam.