Although the developer had only 3 days to make this but it was done really well to a pretty much playable point. The game is really challenging and possibly a little confusing at times on how the mechanics actually works. Note that since the game doesn't exactly feature the main or side theme at all, I will pass on rating the game.
Magical Girl Concept: Since the game isn't actually finished, there is no visual signs of a magical girl in the game.
Mechanics: The game uses some basic movement controls with aim tied to the mouse pointer. There are some well thought of player weapon designs, where the left mouse does a continuous stream of bullets while the right mouse button fires off a powerful burst of bullets which takes time to reload. There is also a really neat melee attack but I notice there is a sort of cool down delay which is not indicated after hitting the melee attack. Its a little difficult to determine the melee attack effective range and there are times when going near an enemy results in being hit rather than being able to execute the melee attack. The health mechanics in the game is kind of unique but not obvious since the health bar is revealed using the shift key which also shows the player character hit box as well as slowing down the movement. I notice there are may instances that the health is replenished when the combo hit counter increases or something else is triggering the health refill. The health packs help in replenishing the health bar but its drop rate is almost close to uncommon. The combo meter isn't very well explained but each time an enemy is hit, the combo bar fills but drops over time. It also resets if the player character gets hits. I'm not sure if the bullet damage gets multiplied by the combo level but it doesn't feel like bullets are getting stronger. Besides that the enemies spawn on each wave, and what type would spawn on each wave seems random, whilst there is some enemies types that would only appear at certain waves. The player bullet is able to destroy enemy bullets and seems to be a vital survival mechanic especially with how enemies and even the first boss spews bullets that do not seem to decay or time out. There seem to be a bug or intentional design that the bullets goes past the boss hitbox and doesn't register a hit when it is changing into its next pattern of attack. Basically, the game mechanics is promising but there needs to be some reasonable balancing and due to its difficulty, providing save checkpoints in the game would be one helpful point for players to actually be able to complete all 25 wave.
Visual: The game basic hand drawn art style is cute and give it a very playful feel to it. I like how that there are many variations of enemy types with its own visual attack while being animated. The player character is animated as well which gives the game quite a good visual sense of movement to the player. However, there is no color or backgrounds in the game, just lineart and placeholders for the first boss. Its not an ideal design choice for full games but if done correctly can be an artstyle some would appreciate.
UI: The game has a simple main menu that lets you start the game immediately and also lets you get back to the first boss wave after reaching the boss level. There is no in-game menu but by pressing Escape key, the main menu is brought up. There is a sort of video tutorial on the controls but I notice the video background is glitching up.
Audio: The game doesn't feature any audio of any kind.
Theme: The developer picked Nuclear Energy as the side theme but I felt that it might have be left out in this version due to time constraints.
Challenge / Engagement: The game is really challenging with the extremely high randomness of enemy types, bullets pattern, enemy movement pattern, and spawning. Some enemy types would give enough time for players to react and some flies straight towards the player character without notice, so dodging in this game is a very continuous activity and at no point I was able to hover in place for more than 1 second. Frankly, I only managed to reach wave 19 after fighting the boss several times and past that I wasn't able to continue further since there isn't a save point in the game. The main menu has an extra button that appears when reaching wave 20 but I don't have the mental stamina to fight the boss just to find out what beyond wave 19. However, the game even though in its initial state is engaging with its current game play but no story or visual aspect are currently present in the game to further enhance the gameplay experience.
Originality / Creativity: The visual aspect of it is quite original with the character and enemy designs and there is some level of creativity in creating the enemy behavior and its initial art. I can't evaluate more since there needs to be more art assets or even a story to determine whether or not the game is original or creative in its own way.
Story: There is no noticeable story except for the curious title which also doesn't explain or indicate that the player character is killing any magical girls until the boss fight begins. I assume the placeholder OHSG art is a magical girl but its not confirmed even with the text description.
Overall: The game is fun to try out and might be beatable if a lot of time and patience is invested. There is a needs to have its difficulty balanced if this game were to be developed for a wider range of player skill level. However, the game should be developed further and lots of consideration needs to be addressed not only visually but the level design as well.