I wanna say, I love this game very much and I playing it too many. I will sort each suggestion for easy read. Here are my suggestions:
Relationship:
- More dialogue. Wish I could talk to them more, by more I mean a large selection of topics. Ask them about each new character that arrives. Ask about their relationship with a character. Wish dialogue options very pretty close to pose count. I just very much enjoying the character's dialogues.
- Each girl may have their own story line (quest). You would progress through it to earn reward. It may related to drill something or talk to character about topic at right time and place etc.
Drilling:
- I like minigame overall but I started to be too powerful for it. Wish I could drill even further after hitting the large red block. New area with new traps and rewards.
- Some unique rewards that you can't get by farming. I really like the new character you find by breaking her coffin, please more like that.
- Having squad slots be upgrade that could increase more (depends on game balance).
Rooms:
- More customized rooms. Furniture you can drop in for them to interact with, that could give more possibility for bonuses. For example different beds.
- Purchasable rooms that girls live in. Moving/swapping rooms for more customisation.
- Rooms that are more drill related like engine room or daycare room that girls don't live in. Girls relationship and reaction varies based on their neighbored room. Like Wolf and Rabbit living close to each other may have some reaction from them.
Prices:
- I think prices right now are place holders (so sorry if those suggestion would not be useful). But everything costing grass (almost) is bad balancing. Just being in grass area I could upgrade everything. Have upgrade for drill that let you travel to other places be related the neighboring areas (for example the water bubble requires seashells then to travel on lava, you would need get water orbs). Each upgrade for drill (that increase range) would include new currency type for each upgrade.
Tech:
- After so much hours I sure that tech is lacking attention. Wish I could see each girl's level up tree (badge) that would show what upcoming upgrades they will have.
- Each 5 or 10 levels the girls will earn new ability. Maybe even at max level their passive ability is permanent (but with lower stats if not equipped as part of squad).
- More obvious ways to level up girls' tech. With Heat, Love and Perv I can see clearly the changes and how it effects the girls. I never seen tech to go up only occasionally would see that the stats are different.
New Game+ changes:
- I think you need to nerf the new game plus requirements by beating all the achievements. Here are some solutions: nerf the achievements requirements or separate new game plus condition from achievements.
- You would have list of what to do, to trigger new game plus as if you building some device. The tasks would be close to achievements but much easier. For each new game plus the tasks are getting harder to finish.