Ambrosia is a Metroidvania, and that's all well and good in its own right. I mean, who doesn't love an open world filled with treasure? But that's not what makes Ambrosia special. For that we need to examine the contents of that treasure: namely, the game's weapons and mods.
Ambrosia uses what we call a "rules-based weapon system." What this means is that you the player build up your weapons by adding unique rules to those weapons -- via parts we call modifications, or mods for short. Because you're adding rules to the weapon, not just static parts, the same mod can produce different results depending on what other modifications and rules have been added to that weapon.
As an example, let's look at the interaction between a few early-game mods.
The Pulse Breaker is a simple weapon. It has three energy cores, which are simply rounds that can be charged up to fire a more poweful shot. So by default, this weapon looks and feels a lot like a certain blue bomber's signature buster.
Cool, now let's add a mod called Core Burst. This mod modifies a weapon's charge to fire all of its cores simultaneously, instead of just one at a time.
Wow! But note that charging up a core overloads it and makes it unable to fire even regular shots for a short time. So while powerful, you'll only want to use Core Burst as a final blow, lest you be left wide open for a counterattack.
Let's add another mod to our Pulse Breaker. Extra Core is a simple mod that, as its name implies, gives us one more core to work with. Now we should have four cores instead of three, which means we can fire in bursts of four instead of three. But wait, what's this?
Since Core Burst charges up and fires all of your cores, adding an extra core to your weapon not only increases the number of bullets you can fire in a row, it also increases the number of bullets created when you charge! But this only applies to Core Burst -- other charged shots will interact with your weapon's rules in unique ways.
Finally, let's add a mod called Splitter. This mod splits your bullets in two, adding a little extra spread to your weapons.
Because charged rounds are themselves a rule applied to your weapon, it means they are also affected by rule changes to that weapon. So our Splitter not only splits our regular bullets in two, it also splits our four charged shots into eight smaller bullets.
A major part of Ambrosia is experimenting with and discovering new and unique mod combinations for your weapons. The examples listed here are just the tip of the iceberg, representing the very beginning of the game. There will be many, many more mods to discover and weapons to play with throughout the course of the game. For me, this is the most exciting aspect of Ambrosia!