It looks like a spin-off from leetchi.com [1] crowdfunding site.
My impression is that the mangopay itself is also more geared towards group-buy etc ventures.
If they do not provide a credit card vault that you can take to another payment company as needed then It's a high-risk option. Just like any other payments company without a vault. Vault is not an issue if the customers making one-time purchases and there's no recurring subscription.
If your biz is with recurring billing then you don't want to run parallel payment systems or ask users to resubscribe whenever there's a need to move somewhere else.
I'm in EU as well and things do not look good for small startups with a need for recurring "mutable" payments. The only reliable option is braintreepayments but 100eur minimum is high and there's an uncertainty with the pricing because of the rumors on Paypal/eBay takeover.
I'm waiting for Stripe to expand to all EU countries. PayMill is very similar to Stripe but their biggest problem for me is not having the vault -- I would not be able to transfer my subscriptions to a new provider if needed (AFAIK, please prove me wrong).
[1] http://www.mangopay.com/about-us/