Voyager had some FPS games (Elite Force iirc) that were fairly standard Quake-Engine early naughties shooters with a Delta Quadrant Flare that were okay, but actually had a clever inventory system.

The way they explained how you could cary a phaser, a compression phase rifle, a special "infinity modulator" for fighting Borg, an an over-the-shoulder mini torpedo launcher, and more was that you had a mobile transporter buffer that held all your equipment, and the weapons would beam into and out of your hands as you changed weapons.