just do your best with textures, and try to get an entry in if you can fx.
yes the poly limit is 2000, a poly is defined by a a single 3 sided triangle.
i say, take a look at your half pip, and see what polys you can get rid of, like ones you'll never see, or ones that add more detail then you really need. Or simplify objects, and then use textures to give it detail.
also, you have to remember, monkey ball tends to go fast through levels...it's not a 'sit around and look at the pretty detail game', it's a time limit 'get your arse in gear' game. So, just keep that in mind when modeling your levels.
also, by my time we are only 3 days into the comp, so you got plenty of time to work on these levels
take your time, and don't rush it, this isn't a SMC, haha! ...hmmm...my silly joke that only i might get right now...blah
MOONDOG