Is the only love interest Commander Mike? or is Doctor Charles available too? If so, how can we get on track for Charles route?
Hello!
Spoilers ahead.
There are currently three possible interests. Nick, Commander Mike and Doctor Charles. As for Nick the very start matters some. As for Doctor Charles, you can start by picking him when you're asked towards the end of the day. There will be a lot more of him in the next update. You're not locked into any one route unless you decide to not encourage Nick, which rather locks you out if his route.
If you want to spend a little extra time with the doctor, pick to not encourage Nick. It does however not influence the romance.
Thanks for reading the story!