My experience there hasn't been perfect but so far it the owner has been trying to help me as much as he can. The cell amount going down is a game mechanic that also exists in agar.io, it tells you in the help document I am pretty sure so I don't think you can say that's a scam based on that. I don't think you can really make a game like this provably fair since it's a game of skill.
Agar.io your blob doesn't vanish immediately. Depositing and losing the entire balance within 30 seconds (when you are far and away the largest blob) is a scam. He deletes every comment Ive made in his thread and accuses me of defamation instead of addressing it. He's a scammer.
You do not know who are the other blobs. You likely will lose to some of
his blobs, especially as the operator officially do not charge anything. He does all the hassle for free? Ha, ha!