If I had 100k EUR I would complete my game-engine, that I am working right now but get disturbed a lot of times to earn the money for living.
As a sample application I would complete a small browsergame and continue to the next iteration of the engine.
This way I can complete, at some time far away in the future, the engine and have designed some tiny games to check if all is working as expected.
Yeah. About a 100k would be enough to have 2 more years of development for me alone. There are some graphics/web designers needed as well.