Hamas never agreed to a ceasfire. They want the military blockade of Gaza to be lifted as part of a ceasefire. They regard the blockade as an act of war. The Israelis will not lift their blockade. The tunnels which the the Israelis have been bombing were used to smuggle items into Gaza. Now that many of those have been bombed, the shortages of food and medicines will be even greater, so the blockade has been tightened. While Isreal are enforcing the blockade, which the UN and EU have said is illegal, then the Palestinians will not stop their protests.
The Rocket attacks from Gaza are more of an act of defiance than a military option. Unlike the Israelis 'Smart bombs' which are computer and lazer guided and are 99% accurate, the Palestinian missiles are just 'point and shoot' and are 99% innaccurate. Of the 10,000 (approx) missiles fired in the last 18 months, just 1 fatally has been recorded.