Biome 3D is a lot like agar.io but in 3D. You play as a blob and eat smaller blobs to get bigger as you move around the map.
Smaller blobs can be eaten by bigger blobs, so you can eat any smaller person or be eaten by any bigger player. You can drop mass in front of you, which can help you lure in smaller blobs or help them out if you're feeling kind. You can also split your mass into two equal-sized blobs and shoot one forward to close a gap.
You can move around with the mouse, move the camera with WASD, and split your blob in half with the space bar.
Have fun and good luck!