Tell HN: Influential games/engines to checkout from the retro ages

Games:

    Isometric + Assembly:
    - Roller Coaster Tycoon (1999)

    3D:
    - Elite (1984) 
    - Battlezone (1980)

    Animation:
    - Dragon's Lair (1983) 
    - Another World/Out of This World (1991)

    Raycasting:
    - Ultima Underground (1992)
    - Wolfenstein3D (1992)

    Terrain mapping:
    - Commanche: Maximum Overkill (1992)

    Simulation:
    - Populous (1989)

    MMO:
    - Ultima Online (1997)