Very well done, and probably the best Shapes file of this whole site. I only give 4 stars though because the physics file glitches randomly and some secrets in certain maps like Waterloo Waterpark cannot be acquired with the physics file. The shapes file boosts the AR accuracy, as far as I know, and some minor other tweaks, noticeable in gameplay. And the sound file replaces absolutely nothing that I could notice. If you want a great physics file, get Aeon of Strife instead.
This shapes, sounds, and physics pack is designed to make the play of Marathon Infinity more realistic. In future, I may modify even more of the game's workings, such as monster movement speeds or attack speeds.
NOTE: This physics model is not designed for multiplayer use; it would make the weapons incredibly overpowered and many maps almost unplayable.