I read a bit and I wouldn't call it a 'Kickstarter-ripoff". It presents a completely different approach, "the European Way", as I would call it.
The good side is that it eliminates most of the uncertainity. For example, the project must be marketed up to two years after funding. Before submission it needs to be revieved by "professionals in the field". The project description must include such things as estimated schedule, marketing analysis and team composition. Gambitious still isn't responsible for scams, but at least honestly tries to prevent them.
The problem are the hoops you need to jump before being deemed worthy to even submit your idea. For a start, your team must be located in EU. They also need to set up a Dutch limited entity. After that, you need to be able to submit a professionally looking business plan. Or hire someone who does, if you can't speak Legalese.
My feelings are somewhat mixed. As a potential donator (or investor), I prefer the service which cares if the people, who use their site for crowdfunding, are actually able to fulfill their promises. I'd also love to be able to actually participate in profits, rather than just in costs. But if I had a small game studio, I would probably never choose Gambitious. Their main competitor is more popular, doesn't require me to hire a lawyer and lets me just throw some promises and watch people shitting cash.