Coffee GB v2.1.5 is released. Coffee GB is a Gameboy Color emulator written in Java 16 (core) and Kotlin (UI). It's meant to be a development exercise.

Features:
Full support for GB & GBC emulation.
Partial Super Gameboy emulation (borders and palette).
Cycle-exact CPU emulation. Each opcode is split into a few micro-operations (load value from memory, store it to register, etc.) and each micro-operation is run in a separate CPU cycle.
Quite compatible (all the Blargg's tests are passed, although some game still doesn't work)
Rollback-based netplay
MBC1-5 support
Battery saves
Support for zipped ROMs
ROM-based compatibility tests run from Maven

Coffee GB Changelog:
This release fixes Razor Freestyle Scooter multiplayer startup and race disconnects, and keeps netplay input logs available only as an internal diagnostic feature.
Starting netplay in Razor now lets the host coordinate a fresh boot of both games with the link connected. The reboot explicitly bypasses autosave loading on both machines.
Opposing directional inputs are resolved consistently, preventing the race disconnect reproduced from a supplied input log.
Netplay diagnostic logs capture every player's input and rollback timing. They are hidden and disabled by default; developers can opt in with -Dcoffeegb.netplay.inputRecording=true. Ordinary input recording and playback are unchanged.
Merged pull requests
#673 — Fix Razor netplay startup and race disconnects, by @trekawek.
#678 — Hide netplay input diagnostics behind an opt-in flag, by @trekawek.
Fixed issues
#663 — Razor Freestyle Scooter multiplayer remains unavailable after loading a ROM before connecting; the follow-up fix also addresses disconnects during racing.
Razor remains in a multiplayer race after replaying the input sequence that previously caused a disconnect
Razor remains racing after the input sequence that previously broke the link (#663).
Known platform limitations
On macOS, game controllers require a compatible system SDL2 installation; keyboard input and emulation remain usable without it.

Download: Coffee GB v2.1.5
Source: Here