Teleport is unique in that it is the only plasmid that isn't meant to harm Splicers. Instead, it allows the player to move around much more easily, escape combat, and relocate to a better spot while fighting. I changed the way it works compared to the original prototype in BioShock, so it could actually work within the game without causing any fatal bugs.
At Level 1, having the plasmid out creates a small circular marker on the ground which indicates where the player will teleport if they use Teleport (in a similar fashion to the Decoy and Cyclone Trap markers). Casting the plasmid automatically teleports the player to that area. Note: If an area is meant to be locked before the player can pass through, they will be unable to teleport near that area. Likewise, the player won't be able to teleport anywhere that would prevent them from completing the game.
Teleport 2 Upgrade #1: Vanish. Charging the plasmid makes the player vanish from sight. During that time, their speed and jump power will be significantly increased but they will be unable to perform any action other than move. Releasing the plasmid ends the teleport and makes the player visible again. While charged, the player's EVE will be drained until they reappear (kinda like the Houdini Plasmid, then). Unlocks Teleport 3 upgrades #1 and #2.
Teleport 2 Upgrade #2: Retreat. Charging the plasmid and firing at the floor releases a teleport marker. The next time the player uses the plasmid, they will be teleported to the marker, destroying it in the process. Charging the plasmid while a marker is already set destroys the marker. Unlocks Teleport 3 upgrades #3 and #4.
Teleport 3 Upgrade #1: Scatter. Player explodes upon reappearing (no damage received), damaging and stunning nearby Splicers.
Teleport 3 Upgrade #2: Fly. While vanishing, the player can fly.
Teleport 3 Upgrade #3: Rescue. Player's health is restored to full after teleporting to a marker. However, this health boost will decay over time until it reaches normal levels.
Teleport 3 Upgrade #4: Safe Haven. Upon teleporting to a marker, all enemies around the marker are teleported to the player's location before teleporting.
And that concludes the singleplayer plasmids section to my idea dump. Thanks for taking a look. Criticism, both good or bad, is appreciated, so post away!