I started submitting an idea for this in line with a game I am presently working on. At a glance, they seem to share profit and everything is ok, but read the rules.
This is what you give up with your entry:
All Entries become the sole and exclusive property of Sponsor and will not be acknowledged or returned. Sponsor shall own all right, title and interest in and to each Entry, including without limitation all results and proceeds thereof and all elements or constituent parts of Entry (including without limitation the Mobile App, the Design Documents, the Video Trailer, the Playable and all illustrations, logos, mechanicals, renderings, characters, graphics, designs, layouts or other material therein) and all copyrights and renewals and extensions of copyrights therein and thereto.
I bet this company has no clue how to reinvent PONG or how to successfully reach the mobile market. Under $50,000 in cash is not worth a real developer's time an intellectual property and that's just the winner. They own every entry, so without getting a dime, they own full rights to every idea in your submission.
This type of exploitation of talent in the form of a gimmicky competition makes me sick. I can't believe I let myself get excited about it at first. Don't let the same thing happen to you.