Modpack Portals+ by Keepitformal

Portals+ offers a variety of new and interesting ways to interact with portals and physics.  Seamlessly travel dimensions with Immersive Portals, or combine it with Gravity Changer and flip upside down.  Both Miniscaled and Pehkui can shrink the player, and Chisels and Bits lets you build in these tiny environments in insane detail.  Every mod included contributes to the mind-bending aspect of Immersive Portals, and the only limit to what you can achieve with such a unique collection of mods is your imagination.  Messing with you friends is strongly encouraged...