Ymir 0.3.0 adds Saturn mouse support, advances Virtua Gun emulation

Ymir’s 0.3.0 release landed as more than a routine Saturn emulator update. It brought the Shuttle Mouse and the Virtua Gun into the project’s orbit, but the bigger story is how those additions push the emulator toward newly playable Saturn software while the core keeps tightening its accuracy.

The Shuttle Mouse is the immediate win. Ymir now supports the Saturn’s four-button mouse, with no wheel, and the buttons map to the Standard Pad’s A, B, C and Start inputs. That opens the door to games and menus that were clumsy or inaccessible without proper mouse input, turning a niche peripheral into a practical part of the setup instead of a curiosity buried in compatibility lists.

The Virtua Gun is the more complicated piece. It is still experimental, and 0.3.0 only exposes mouse support in the stable build because the light gun work is not ready for the same treatment. The release notes make the limitation plain: the gun is really only usable with House of the Dead right now, and it depends on SMPC PAD interrupt support, which explains why it remains a nightly-build feature. That kind of candor matters in Saturn emulation, where input devices often reveal how much of the console’s behavior still has to be rebuilt before a game feels right.

For testers and tinkerers, the save-state changes may be the most useful addition of all. Ymir added undo support for both save states and load states, so a bad overwrite no longer has to become a lost checkpoint and a mistaken load no longer has to trap you in the wrong branch of a test. The emulator now keeps one extra save state per slot and one global load state to make that undo workflow possible. Combined with existing rewind support of up to one minute at 60 fps, frame stepping and a feature-rich debugger, Ymir is increasingly built for the kind of trial-and-error that Saturn accuracy work demands.

That push shows up again in the SH2 debugger refresh. Version 0.3.0 added Data Stack and Call Stack views, made the viewport navigable, and let breakpoints and watchpoints be enabled or disabled without being removed from the list. For Saturn emulation, those are not cosmetic touches. They help track down the kind of timing, interrupt and CPU-state bugs that separate a playable build from one that only boots. With Ymir already described as a work-in-progress emulator released in early 2025 and later reported at more than 90 percent compatibility, this release read like another step in the accuracy race, not just a convenience patch.

StrikerX3 also kept the release grounded in everyday use, warning Windows users to install the latest Visual C++ redistributable, reminding macOS users about ad-hoc signing, and telling Linux Flatpak and SteamOS Discover Store users to grant filesystem access for disc images. Ymir 0.3.0 did not just add toys. It made the Saturn harder to ignore.