No videos or pix today... Laziness! Let's instead delve into the more theoretical world of Moon Invaders. This is stuff that doesn't actually exist yet, it's just the ideas behind the design.
At its core, Moon Invaders 2 is a 'roguelite' (because that is mandatory in 2021 game development). You make runs at the game over and over, and each time you fail (or win), you come back with currency you use to upgrade yourself so your next run is easier. Much like in Monster Train, winning grants you an increased difficulty option to match your clear superiority, but you don't have to take it, you can always play an earlier difficulty. There's an in-game logic to all this (because I have a weird obsession with having a reason behind the rules) but I'm not spilling the beans just yet! When you lose, you stay at the same difficulty (or you can backtrack to lower ones, if you like), and can hopefully upgrade with the stuff you got.
So design-wise, the gameplay consists of 3 nested loops:
1. At the smallest level, you are playing "zones" (the different map locations). When a zone starts, you have no turrets and a certain amount of cash, and you need to buy and upgrade towers to blast the aliens before they destroy you. Defeat a set number of waves and you win. Fail and your run is over. The concept here is about smart decisions in when and what to upgrade so that you don't get overwhelmed, like all tower defense games.
2. At the next higher level up, you are playing through the entire moon (a series of zones) to beat the bosses. You earn loot when you are playing each zone, which you can equip between zones to make you stronger. Good thing because of course the zones get harder. This is RPG-style gear, with stats that do things like "Blastor towers deal 10% more damage" and all that. So the concept here is about gearing up and randomly getting good stuff and choosing the right combos (probably not very hard choices, but it's always fun to be making them).
3. And at the highest level, you are making multiple runs of the moon, starting with no gear each time, until you beat it (and when you do, you still keep doing runs because now it's harder!). It's here that you spend points you earned during your last run on a giant skill tree. This mostly consists of unlocking new tower types and upgrade slots and upgrade types, but also other general upgrades. So here we have the traditional skill tree, build your character, type of concept. You can invest heavily into missile towers, or get into lasers, whatever suits you.
So as you can see, it's a bunch of upgrading! There are a bunch of other twists and turns but this is the core idea. In each loop there's a different kind of upgrading, but the bigger loops affect the smaller loops. So you're always getting stronger, and isn't that what gaming is about? I know gaming certainly hasn't made my
spine collapse into a gelatinous mass over the years.