Block Blast is proprietary software owned by Game6. Distributing modified APKs or decompiled source code violates copyright laws (DMCA in the US, CDPA in the UK). Repositories that host such material are frequently taken down, which is precisely why an "exclusive" hidden repo exists.
If you want to play Block Blast at school or work (where the app store is blocked), look for unblocked HTML5 clones on sites like Cool Math Games. These are not the "76 Exclusive," but they offer the same core mechanics without malware risks. block blast github 76 exclusive
Before you rush to search for this elusive repo, understand the risks. Downloading game mods from unofficial GitHub accounts carries significant danger. Block Blast is proprietary software owned by Game6