Fullscreen, and snapping the desktop window to aspect.
Sunline has an immersive fullscreen mode that hides every overlay — the clock, the activity LED, the player, the banners — and shows just the map. Useful as an ambient display, or for a clean look on a big monitor. (Tapping the map still summons the top‑right control row, so you always have a way back out.)
Two things are deliberately allowed to break the silence: the Time-lapse timer's 30‑second warning (E2) — because a fullscreen time-lapse ending unannounced would be worse — and the orange FPS box (E4), which appears only while the app is actively throttling itself.
Enter and exit fullscreen one of three ways:
On mobile, the platform's system UI (status bar, navigation bar) is hidden as well in fullscreen mode.
(Desktop, flat map only.) The flat map has a fixed aspect ratio (2:1). If your window's aspect doesn't match that, the map is letterboxed and the unused space is empty.
When this happens, an extra icon — Snap window to correct map aspect — appears in the top‑right controls. Tap it and the window is resized to exactly fit the map's aspect ratio, removing the letterboxing. The icon only appears when there's actually a meaningful mismatch, only on the flat map, and not in fullscreen; on the globe, the view fills any aspect naturally so it isn't needed.