forget them you can't 1337 h4x Blockland. Believe it or not, but it's god damned magical.
No, it's just pure Server <-> Client
The reason other games get hacked is because they use peer to peer (good but vulnerable), or actually calculate stuff on the client for some reason.
With everything on Blockland being calculated and processed on the server, it makes it impossible to hack. The only thing you can do is bot.
Peer to Peer games generally have the client prevent funky stuff for their 'hack protection', which generally only works for damage.
I've seen a Server <-> Client game (MMO) actually let the client determine how much damage they do. This has to be the worst development I've seen.