This is a great idea, but as many people have said, the card is underpowered and it should be changed to make it more effective. The concept to block creature slots is already used by Aflatoxin, which overshadows this card.
There are many ways to buff this card. It could block the first unused creature slot, so it has synergy with Flooding. If used early in the game, this card could lock down your opponent with Flooding or severely interrupt their strategy. This card is much cheaper and more affective than Aflatoxin, so in the above situation it is much better than Aflatoxin.
Another way to make this card more effective is to select multiple, random creature slots that are blocked. If it blocked three random creature slots, it has the potential to be much more effective if you run six in a deck. It would be cheaper than Aflatoxin, and it would require less quanta to upkeep than Flooding.
Both of the above ideas utilize the cheap cost of this card. While the effect is overshadowed by Aflatoxin and Flooding, the 2/1 quanta cost makes this a candidate for fast lockdown. A deck with a combination of this card and the aforementioned cards would create new strategies to complete control the opponent’s field. A poison deck with Aflatoxin, Blockage, and Enchant Artifact could lock down the opponent fast while the poison kills them off. A deck with Flooding, Blockage, and Trident could stop the opponent from playing creatures, and then destroying pillars to make it a complete lockdown.