The Task system is pretty much that. It won't prevent you to win in a "standard" way, but it rewards you with more credits if you accomplish the tasks.
So, for example, if the task is "bury at least 20 red cards to your opponent's graveyard for 200 credits", it means that for your next match, you have to get an opponent with red cards, and make sure you "don't win too fast" in order to be able to have 20 red cards in the AIs graveyard when you win.
Other tasks involve "Reach immortality (1000 life)", (which basically requires you to play with
Beacon of Immortality, I don't know any better way), or simply "
Defeat deck A before turn 15", or the opposite "
Defeat deck B after delaying it for at least 30 turns", stuff like that.
Currently the system is extremely simple and just looks at the state of the game once the game is over (and compare it to the goals of whatever tasks are current). But it could be doable to add statistics in the game, to make sure that the player never attacked with more than 3 creatures, or things like that. Which could achieve what you are looking for.
I see no technical issue to add that kind of feature in Forge, but one "gameplay" issue: Wagic has a credit system, one has to unlock and "buy" the cards before they can add it to their decks. So rewarding with credits is an easy way to do it. But in Forge, what would be the reward for completing the tasks?
Here's a screenshot that says more about the tasks: