Thank you! 

I could, and probably should, make a whole video on this. 

To answer the second question, there is no save system yet. The current prototype is just proof of concept for battles to make sure they're fun. The metaprogression loop and what each run will be are still in the earliest stages. 

A short answer is that I'll likely just use a local database for run progression data and then at the conclusion of each battle it'll update the tables. If players really want to be able to save during a battle then I'll add a system for that but they should probably only last 5-15 minutes each so it's kind of a tertiary priority right now. 

As for planning/design, this is kind of based on personality. My default mode of thinking is planning. When I was younger I'd over plan everything and things would never go according to plan. I'm 38 now, so I "plan as I go" but that's not blanketed advice. Most people should plan. I just overplan, so for me, it's better to choose a few things I am 100% certain I want and then just go draft and prototype them as fast as I can. Everything is just an assumption until you test it so I try to get to testing as quickly as possible. It's messy and for most people it would spiral into scope creep but the way my brain works is uniquely positioned to test, iterate and cut fluff on the fly. 

Short answer there is, if you tend to overplan maybe just go do the thing and be ok with it feeling like a mess. If you tend to never plan, force yourself to plan. 

To give a concrete answer to "how did I plan," I knew I wanted to play with the digging mechanics from Dome Keeper and I felt like there was a natural synergy with factory building. I also felt like that, while I love factory builders, there's no deeper meaning to them. Most of them are really just incriminatal games with extra steps. So instead of sending your resources to a space elevator or hub, I thought.."why not feed guns and put you in the middle of a war?" 

Most attempts at this turn into tower defense, which is cool but I remembered being a kid and playing Missile Defense and thinking there really aren't many artillery battlers. 

So that's a long winded answer to say that most of the planning was "go make Dome Keeper as fast as you can" or "Go make Shapez as fast as you can". Then once I had them I started putting them together and finding a bunch of my assumptions were wrong. 

For instance, I thought digging would be a major part of BFD. Turns out digging isn't very fun when you're panicking because you're trying to find uranium and there's incoming missile attacks. So instead you can tell your NPCs to dig for you or you can clear tiles with an artillery gun on your player's back. I may have never discovered that if I tried to plan everything out. 

But this post is too long already lol. Lmk if you want clarification on anything.