You will without doubt get this achievement when grinding towards destroying 500k blocks. All time in the game seems to count towards the achievement.
If you just want to earn these achievements with as little effort as possible, there does exist a simpler method. You can disable your screen timeout (Settings>Lockscreen>Screen Timeout>Never) and leave the game running unattended while in a level for long periods of time with the phone plugged in. Make sure when you are done to complete the level by passing or failing to save your time. NOTE: This trick is not possible on all devices (screen timeout will be limited to 5 minutes). For those of you that cannot disable your screen timeout, you will need to grind this the old-fashioned way. Load up a level and let it sit while you do something else, making sure to tap the screen periodically before your timeout limit is reached. Just be sure to complete or fail the level when you are done grinding for the time being in order to save your accumulated time.