This achievement will most likely need to be grinded after completing the game as well. As far as I can tell there are no "great" levels to boost this on, but there are two that are better than the others. In Level 1-18, you get three laser birds to shoot, but there are not that many blocks to destroy. Focus solely on hitting the wooden blocks, as the laser does not work well against the metal. Level 1-21, you only get two laser birds to shoot, but there are more and smaller blocks to destroy. Focus on hitting the wooden and ice blocks and avoid the metal ones. Personally, I find Level 1-21 a tad faster. Pause and restart the level as soon as all of your lasers are gone. You can destroy between 8-10 blocks per attempt of the level, earning around 40 blocks per minute. All 1000 should take around 25 minutes or less to grind.