Crystals are the required collection objective in Crystal Maze 3D. In ordinary levels, completing the crystal counter reveals the golden key. Picking up that key opens the portal. Follow this sequence rather than looking for the key while required crystals remain.
Check the counter
Read the counter in the running game before leaving a branch. Coins and gems are separate pickups: collecting them does not mean the crystal objective is complete. If the portal stays closed, first check which required step remains.
Search the maze methodically
Look along each branch at a junction, choose one route and revisit the alternatives when it ends. The layout is generated for each run, so a memorised crystal coordinate from another run is not a reliable location. Use the minimap and visible passages to organise your search.
The final maze
In the current embedded build, collecting all crystals weakens the final boss and opens the exit directly. This differs from the ordinary key sequence. Check the live objective indicators if the publisher changes the build.
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