an open source golf game like tiger wood would be nice 
here a suggestion for the game engine u could use if you want to make one 
if your going to do a open would game please take a look at the open source engine called Grit 
http://gritengine.com/The Grit Game Engine is a community project to build a free game engine
(and pipeline tool-chain) for implementing open world 3D games
While there are many open source game engines, ours is the only one that
is being optimized for open world games. We support large maps (e.g.
more than 30 square km, 50000 objects) with considerable diversity in
geometry and textures, because game objects and scenery consume
negligible memory / CPU resources when out of visual range. We also use
deferred shading, which is essential for rendering the abundance of
light sources that are needed in open world scenes.
    Code is open source and MIT licensed.
    Large open world maps, content streamed from disk.
    Normal / specular / gloss maps
    Heightmap-based texture blending
    Deferred shading
    Soft dynamic shadows
    24 hour time cycle with sun, moon, clouds
    Stars at night with real constellations
    Procedural placement of vegetation and clutter
    General purpose 3D physics engine.
    Game objects are extremely scriptable via Lua.
    Planes & cars (implemented via game object scripting).
    Developing/debugging scripts is easy thanks to an in-game Lua console.
    Linux and Windows ports are available.