Fuse is an emulator of the Sinclair ZX Spectrum home computer. It supports all of the original models and some clones, with quite faithful emulation of the display and sound.
Fuse can load most formats of snapshots, tapes and floppy disks and it can emulate many peripherals such as joysticks, printers, storage devices and network interfaces, among others.
It's easy to use. It starts the game without any problems. Works smoothly. Flatpak works fine.