Interesting. I had a very similar initial experience [1]. I got sick from Half Life 2 the first two times playing it, but the third time I managed to do a 40-minute session without feeling any serious nausea. It's definitely something you can train yourself to tolerate.

But srsly, 4K resolution is an absolute must.

[1] http://www.colorfulwolf.com/blog/2013/10/02/oculus-rift-dev-...