Flame Trap: Play on a base. Ongoing: After another plays a minion here, destroy it (resolve its ability first) and this card.
Lets say we play a Zapbot or one of the Micro's which allows someone to start chaining minions onto a base. Does the Flame Trap destroy all of them? Since the abilities are resolved before the card is destroyed, if you chained out 5 minions onto that base, does it destroy all 5, or only the first one which triggered the trap?
I personally feel that the card reads "Destroy It [it being the card which stepped on it] and this card." Nothing more nothing less. It does not then apply to the monsters which have been chained out due to the ability of the first minion.
You play a Zapbot. The Zapbot gives you an extra minion of power 2 or less this turn. It is then destroyed with Flame Trap.
Later on you play you extra minion. It is not part of the same action, it's a separate one. The 'chaining' is just a convenient shortcut that people do. In reality you're playing each minion individually.
Also: If the minion is the robot that cannot be destroyed, congrats! You just got rid of a Flame Trap at no cost to you (Flame Trap triggers and destroys both itself and the robot, but that robot can't be destroyed, so only Flame Trap is destroyed.)