Once pressed, all the hazards will be disarmed - spikes will retract, Red Poop will transform into regular Poop, Red Fire Places will turn into regular Fire Places, Purple Fire Places will turn into Blue Fire Places, and Pitfalls will close.
Unlike Reward Plates, all Silver Buttons in the room have to be pressed to clear the room even if all enemies are slain.
Bug!
In trap rooms with retracting spikes, pressing the silver button within five frames of the spikes deploying will cause them to appear to fail to retract, but this is only a visual bug, and they will not deal damage. This can be fixed by leaving the room and re-entering.
Reward Plates can appear in a variety of rooms, including Secret Rooms, Curse Rooms, and Shops in Greed mode. When pressed, they may spawn helpful pickups or harmful enemies.
Walks around the room, avoiding Isaac while spawning Attack Flies. Spawns a large number of flies upon death, which can be Flies, Attack Flies or Pooters.
Chases Isaac, dealing a full heart of contact damage. Upon taking enough damage, it collapses into a pile of goo, which can be killed. Will regenerate after a short period of time if not killed quickly.
Slowly walks towards Isaac. Occasionally leaps off-screen and attempts to land on Isaac, leaving a puddle of Red Creep and shooting 6 blood shots in all directions where it lands. Has a chance to turn into a Blubber upon death.
Falls from the ceiling. If it lands on Isaac, it deals damage and teleports the player back to the spawn room of the floor. Entering a room containing Mom's Hand will warn the player with Mom's laugh.
Slowly moves around the room, charging at Isaac when he gets in its line of sight. Explodes into four blood shots in the ordinal directions upon death.
A Reward Plate may spawn a trapdoor even in The Chest. If that happens and Isaac enters them, the floor is restarted as with Forget Me Now or 5-pip Dice Room.
If it spawns enemies, the doors to the room will not close, allowing Isaac to avoid fighting them.
It may be worth fighting Sins as they still drop items on death.
This was changed in Booster Pack #5. If it spawns enemies then the doors will close. The enemies will remain in the room even after escaping via teleportation or bombing out.
When enemies are spawned, they appear only at walls with doors (barring an I AM ERROR room where the locations are random). This may help locating Secret Rooms as their secret doors also count.
Different enemies may spawn from the buttons depending on the floor, with difficult enemies such as Bosses being spawned on later floors.