The review likely highlights the unique "lock-on" technology, where Sonic & Knuckles combine into one massive, definitive game. Optimal Playability:

Leo pressed the arrow key. Right.

• Play via Sega Genesis Classics on Steam (if your network allows Steam).
• Play via Sonic Origins (which includes a remastered version).
• Use Archive.org (which operates under library lending exceptions).

was split into two separate cartridges—Sonic the Hedgehog 3 and Sonic & Knuckles—due to time constraints and cartridge storage costs. Sega’s solution was the innovative "Lock-On Technology," which allowed players to physically stack the cartridges to unlock the full, unified experience.

Searching for this title "unblocked" suggests users are looking to play this complex, high-quality platformer in browser environments (like school or work) that restrict gaming sites, usually via emulation. Hidden Features:

how/where can I play sonic 3 & knuckles? : r/SonicTheHedgehog