Sayonara is a small, clear and fast audio player for Linux written in C++, supported by the Qt framework. It uses GStreamer as audio backend.
Seinnteoir meáin clasaiceach
Media Player Classic Home Cinema (mpc-hc) is considered by many to be the quintessential media player for the Windows desktop. Media Player Classic Qute Theater (mpc-qt) aims to reproduce most of the interface and functionality of mpc-hc while using libmpv to play video instead of DirectShow.
Naisc Gnome
A remote desktop client for the GNOME desktop environment
QMPlay2
QMPlay2 is a video and audio player. It can play all formats supported by FFmpeg, libmodplug (including J2B and SFX). It also supports Audio CD, raw files, Rayman 2 music and chiptunes. It contains YouTube and MyFreeMP3 browser.
caiféin
Kaffeine is a media player. What makes it different from the others is its excellent support of digital TV (DVB). Kaffeine has user-friendly interface, so that even first time users can start immediately playing their movies: from DVD (including DVD menus, titles, chapters, etc.), VCD, or a file.
Haruna
Haruna is an open source video player built with Qt/QML on top of libmpv.
Pragha
Pragha is a Lightweight Music Player for GNU/Linux, based on Gtk, sqlite, and completely written in C, constructed to be fast, light, and simultaneously tries to be complete without obstructing the daily work. 
Videos
Also known as Totem, Videos is a movie player designed for GNOME.
GMusicBrowser
A customizable open-source jukebox for large collections
KBlocks
KBlocks is the classic falling blocks game. The idea is to stack the falling blocks to create horizontal lines without any gaps. When a line is completed it is removed, and more space is available in the play area. When there is not enough space for blocks to fall, the game is over.