Ask HN: Doubts on NDA and side projects

Hi guys, I've found work like contractor in a startup incorporated in delaware, but with HQ in SF. I've a doubt about the NDA that they want me to sign.

Here there are the most important parts:

INVENTIONS

a. Inventions Defined. "Inventions" means inventions, original works of authorship, developments, concepts, improvements, designs, discoveries, ideas, know-how, trademarks, and trade secrets, whether or not patentable or registrable, under copyright or similar laws, that Consultant may solely or jointly conceive, develop, or reduce to practice while performing services for Acme Corp. during the engagement.

b. Assignment of all Rights in Inventions; Disclaimer of Rights in Copyrights . To the extent that Consultant, as a part of Consultant’s services to Acme Corp., contributes to the development or creation of any new Materials on behalf of Acme Corp., Consultant hereby assigns all rights to such Materials, without any claims or demands for royalties or future payments whatsoever.

NON COMPETITION AND NON SOLICITATION a. Non-Competition. Consultant shall not during Consultant's engagement directly or indirectly render any services of a business, commercial or professional nature to any other person or organization, whether for compensation or otherwise, which would prevent Consultant from rendering the agreed services to Acme Corp. during Consultant's engagement.

(or github for better format: https://gist.github.com/inchr/13165c2a2f792b23417f )

I don't properly understand the part about the inventions...I must give them the IP of the work done for them, or I must give all the IP(also developed for my side projects, in my free time) ?

My question is: I'm allowed to work on my side projects in my free time ?