I'm not sure irregular updates are the only problem here. The third game also had pretty irregular updates but was still active. I don't think more regular updates would fix the problem.
Interest in forum games in general has decreased considerably, probably because the GMC (and especially off-topic) userbase is different now. Unfortunately, not much can be done about that.
And, fun wise, you're still new. If you're still willing to update the game, if you still have the motivation to do so, this could work just fine. It's not like anyone expects you to make something amazing right away. But, with just a bit of experience, I'm sure you can make the game pretty great. If we ignore the irregular updates, you're doing fine right now.
And if you don't feel like you'd be able to remain committed to this, then letting someone take over is probably a fairly reasonable course of action. I could take over, but only if no one else does and if the alternative is just letting the game die. I don't know yet how much time I'd have to update the game if I took over, so I want to avoid taking over if possible.