If your deposits are insured, then sure why not? If Japan's able to enforce deposit insurance on licenced exchanges, surely a Gemini-backed entity must be able to do the same, especially if they're soliciting your deposits.
2% annual interest is not worth the risk, as pointed out. If you REALLY wanted to gamble, there is a service here that lets you earn about 4% annually (compounded), crediting you daily, and funds never locked. Hint: They're in Gambling section and are one of the most read and responded to threads. They've not scammed anyone for 4? 5? years but I wouldn't store my precious savings for that kind of interest. A little here and there, sure.
It's 6% for the first 500 ether
what is that service you are talking about? I suppose there is still counter party risk? If not even more?
Still not worth it, my friend. In fact, I'm still not sure any amount of interest is worth it, and that they're actually lowering interest rates is a sign that even they can't make as much as touted.
Anything guaranteed just sits uncomfortably with me, because there's no such thing. Like I said, though, if deposits were insured, like they would be in a bank account, that's a different story. That's what you should find out (and I'm more than certain they don't).
The service I'm talking about is freebitco.in. Probably the oldest faucet around? That's the same risk I'd say, putting your money and hoping they never run away. They've never scammed, but past performance isn't a guarantee of future, right?