Trove
43 Achievements
1,700
1000+h
Blockbuster
Destroy 1,000,000 blocks
50
0.09%
How to unlock the Blockbuster achievement in Trove - Definitive Guide
That being said, I believe the fastest way to get this achievement is using the Boomerang class. The Boomerang class's RB ability is to drop a bomb. Used correctly, this bomb can get you 250~ blocks every time.
First, dig straight down until you are very deep in the ground. Drop a bomb and throw a boomerang. Every time you throw a boomerang it reduces your cooldown time. Then, switch to build mode and dig straight forward like 3 depth. Throw your boomerang a second time and you'll have your bomb back. Rinse and repeat.
With this technique, you only have to repeat roughly 4000 times. It will take you around 9-12 hours of doing it repeatedly.
Any type of block will count toward this. Regular green ones in the starting zones, Infinium Ore, etc. Lasermancy is the main stat that affects how quickly you break down blocks, so if you want to work on farming for this achievement, get some gear that will buff it. If you're a Patron (paid subscription), you get +50% to this stat, which will make this go much faster.
The best type of block for this I've found to be the ice blocks in the Permafrost zones (light grey on the map) or glass blocks in the Neon zones. Both of these blocks basically break the second your beam touches them, so you can rack up a ton quickly. You need to be in Build mode to break down blocks with your laser, so hit the back button whenever you need a specific type of ore/block, or just if you want to break some as you walk from one dungeon to another.
If you have a flying mount, most of these will shoot fireballs as you fly (with ). Doing so will break the ground and give 15-20 blocks each time. You'll be flying from dungeon to dungeon often, so spam those fireballs while you go to whittle away at this.
The best option for farming this by far though is using bombs. To save some time and materials, make sure you unlock the Boomeranger class and use the bombs while running around the world adventuring. All this destruction will chip away at the achievement. If you're specifically working on the achievement, dig straight down before using the bomb for maximum effect, then tunnel forward and repeat (this way there are blocks on all sides rather than just below you if you used it on the surface).
The plan of action is this: we take this very dragon, put on the gear for a large number of jumps, jump higher and start spamming R2 . At the same time, you can mind your own business...