Coceter Chronicles is a great one, my favorite game, the MC isn't in any committed relationships though there are relationships that can happen.
High Life is only in its first version, but it looks really promising, MC has no ties.
Kingdom of Deception is quite entertaining.
I Love Daddy is a great little visual novel if you don't mind heavy incest content.
Project SAGE is also great, as far as control over your protagonist, only Coceter is on par.
You said not lesbian, did you mean no lesbian? If not, my game, Seraphim Academy might also be a good fit for you. Most of the romance options are female, but it isn't intended to be a pure lesbian game, and the male romance I have planned should be fun.