Amid Evil is an old-school shooter with a big catch, you don't use guns you use MAGIC
Story
The realms of the universe have been corrupted by a force from the abyss turning them...well evil. You play as the Champion, and it's your job to eliminated the evil forces from each world and then from its source.
Gameplay
I'm not very familiar with playing old-school shooters (I had only seen some streams), but there are a lot of standard elements you expect such as picking up stuff by walking, you move really fast, secrets, instead of ammo you have colored mana,etc. So I will focus by talking about the standout features, that of course being elements magic.
There are 7 weapons
Axe of the Black Labyrinth: It's an axe that hits hard, not much to say. The initial animation is very slow, so hold the "shoot" button to widely swing it. On Soul Mode becomes a grinder and propeller.
Staff of the Azure Ore: It fires blue homing orbs which makes it perfect for enemies that are too far away or move too fast. On Sould Mode the Orbs hit harder.
Whispers Edge: A sword that shoots sharp projectiles, the sides can hit multiple enemies making it useful when facing groups. On Sould Mode the projectiles are larger and bounce.
Voltride: A trident that shoots beams of electricity, when you kill an enemy with overkill it damages nearby enemies, good for crowds but it requires a good aim. On Soul mode the beams are thicker and and powerful.
Celestial Claw: It looks more like a branch tbh, anyway it pulls planets shrinks them and shoots them at enemies causing an explosion that can hurt you, and also the planets could had life so make every shot count. On Sould Mode it pulls stars.
Star of Torment: An ice-cold mace it shoots ice shards on a spread pattern so it's better to use them on close range enemies. On Soul Mode the projectiles seek enemies.
Aeturnum: I can't describe how it looks except it's purple. It's the room clearing weapon fires a projectile that flies for a bit and then shoots electricity beams on all directions killing enemies. On Sould Mode it shoots a black hole that pulls enemies.
But what is Soul Mode? Whenever you defeat an enemy it drops a soul you can pick up, collect enough and you can enter in Soul Mode which powers up your weapons. You are not invulnerable during it.
Magic in the game is great, very creative, colofurl, flashy and more games should use it instead of guns. What's interesting is that I find that I rely more on the weapon gimmicks (homing, AOE, etc) rather than X enemy is weaker to Y (too many RPGs I guess), but I did felt that the farther away enemies were the less damage they took.
Level Design
There is a hub world with the 7 realms to save plus the final one with 3 levels plus a boss level on each. You can visit any realm on any order (minus the final one) after the first 2.
The levels are design to be speerun so they aren't long (8 minutes or less) if you know what you are doing. The are also moreless linear with secrets (somewhat out of the way) for you to find, usually containing health, mana, a temporary powerup or a weapon. The last one being the most important at first because whenever you return to the hub world you only have the Axe. You do get your arsenal back as you progress but you can get it quicker through secrets.
There is also minimal platforming, nothing complex but you can find secrets through it.
The levels can have facinating architecture. The most interesting architecture for me was the one in the Arcane Expanse, it's Space Wizards themed), with the most standout level there being Hexed Corridors, it's a "maze" with impossible geometry (things look smaller on the outside than on the inside). And the most boring being The Sacred Path because it's just ancient temple themed and i didn't feel they do anything interesting about it.
Enemies
Each location has their own set of enemies there isn't a great variety but I never felt a need for it partly because it isn't a long game and partly because how they were placed made it more unique, it made me think what weapon is better for the ocassion, and pay attention to the sound of tougher ones. That being said ambushes are common on this game. Personally I didn't have a problem with them since they were spaced out, kind of predictable, challenging and a good reason to use Soul Mode. But on the other hand it made me save it for when I need it.
As for Bosses they are a special strong enemy with unique attacks that you fight 1v1 just using weapons, no puzzles except one that requires removing its invulnerability. However, something I found out at my third boss and that you might not wanna know if you are going to play the game: Minus the last one they are weaker to a specfic weapon on Soul Mode.
Minor Stuff
I experience a 3 times the AI stopped existing and enemies just stand there.
Whenever you pick something the screen flashes blue everytime, which can be annoying (or dangerous) when you picked up a lot of stuff in quick sucession.
Final thoughts
Really good game and more devs should use creative magic instead of guns.