Now that the leveling system is in, after playing around with it, I think there’s a lot of opportunity for making it a lot more engaging and immersive. Also, there’s a few things that I personally dislike: the incremental cost of leveling attributes and having them draw from the same pool as skill points, plus the complete randomness of the secondary skill tree.
The incremental cost system creates 2 “problems” that makes it unfun (for me atleast): it makes calculating the needed points to reach a certain threshold annoying and it leaves unused points between levelups and at max level. This would promote jack-of-all-trades soldier progression if you don’t want to have too many points wasted at the end. In addition, having them in the same pool as skill points, I think most people would probably just spend the points on skills exclusively for the first half of the game, until all critical skills are taken and only then try to see what remaining points can be dumped into attributes.
Consider also a system where all skill points are moved to the general pool (Phoenix SP) available to all soldiers instead of having individual skill points. This would create a more dynamic system where the player can decide whether he wants to focus more on certain soldiers for his A-Team or spread the skills around more to have backup available if something happens to the main soldiers.
So, a suggestion would be that on level up a soldier can get his personal pool of attribute points and unlock access to new skills, depending on level (but no personal skill points). Completing mission objectives and finishing missions successfully provides the skill points in the Phoenix SP pool. From a thematical point of view, a level-up would mean that a soldier improves his physical and mental capabilities (represented by the strenght, speed, willpower attributes) and then he can use the common knowledge of the entire team, acquired from succesfull operations, to be trained in specific class or general skills.
Secondary skill tree:
Right now, the secondary skills (non-class specific) seem to be just too random. I would at least like to have certain skills grouped up based on synergies and equipment available to the class. So if you’re a heavy, there’s a higher chance to get heavy and mounted weapons proficiencies and expertise, rather than melee or silenced weapons or expert healer and stealth specialist. Also, the secondary tree can be populated only up to level 3 and once the multi-class selection is made, the rest of the skills can be generated.
Or, I would propose a system that is more engaging, gives complete choice to the player and removes most of the randomness: provide a Training Facility in the base and build each soldier’s secondary skill tree by picking what skills to train in between missions. Start with only the proficiency skills available and once learned, the corresponding expertise skill is unlocked so it can be trained and so on, with stronger utility skills like expert shooter unlocked when a certain number of proficiencies or certain skills are trained. Of course, the slots available for trained skills are based on the soldier level (and available skill points in the general pool), so at level 1, only one utility utility or proficiency skill can be trained, at level 2, you can train either an expert skill or pick a different utility skill etc, until you can train all 7 slots at level 7 (or whatever is the max level), if you have the necessary skill points. In addition, you can also keep an aspect of randomness, by considering that soldiers may already be proficient, or show aptitudes towards certain skills, thus making those skills trainable without a cost. So the player can decide whether he wants to save skill points by focusing the training on what a soldier is already good at, or specialize him towards the player’s prefered tactic.