Don't let that hold you back MissMimi, these contests are judged on a wide variety of criteria. Builds that don't use mods but are extremely well done are considered even more challenging than a similar one done with them. Besides, the point is to have fun and show off creativity... so go for it!
There were many excellent entries this time around, and the Survival Plus spotlight in particular caught my interest when he mentioned new detailed and individualized creature behaviors.
Thanks again for hosting the contest and undertaking what must have been a particularly challenging judging process this time around.