Sea Outpost requires the "Wave Drill," "Craside Brewer," and "Repair Turret" items, but they are unobtainable as the resources necessary to make them are not present on Cave Entrance. This makes it impossible to progress campaign gameplay.
Another issue is the way some things are designed. Typical Mindustry levels should have mines close to the enemy in waved sectors, so you can set up resources there. Not only this, but the fact that the enemies in Cave Entrance spawn very far away, so you need to set defense around your core, which if you've played Mindustry past Frozen Forest, you would know is an absolutely terrible idea and incredibly awkward to execute.
The third and final issue is that there are minable Fors that should be able to be mined by normal drills (i.e; Mechanical, Pneumatic, Laser, and Airblast drills), but there are no unlocks that let you mine them with anything except your core unit. This was very likely designed for drill use, but they weren't added, making resources scarce and hard to collect, which in turn greatly decreases the quality.
Issues aside, I loved the art and concepts this mod brings. There are just a few things to work out :)