Interesting! Very fast and hard to tell what impact I'm having by turning the cells gray... I can't learn the behavior of the army cells and it's difficult to parse what's going on so quickly, at least for me.
Looks nice visually, when it first booted up I thought it was a cool loading screen for the game until I realized that quick pixel animation was the game haha...
For arcade survival games, I highly recommend including a timer or other kind of scoring system. Timers are very easy to implement, though, and are often just better as everyone can understand them. Simply time how long it takes for the player to lose so that players have something tangible to compare between each other and between their own runs. Hold up that number as the game score, and keep a running high score for players to try and beat.
I'd also recommend sprucing up the game page; hit Edit Themes on the page and add some non-default colors. I often find it's easy and best just to copy colors from the game as the background and text colors! Just make sure to make the text as readable as possible, including / especially from a distance. I recommend a dark central background color and light font color, and don't go too crazy with the font. Thematic fonts are cool, but readability is more important!
Add some screenshots, which is good practice. Add more tags and more metadata with the other tabs when you edit the game page, especially the "Average play session length" or whatever it's called... The more information you give itch.io, the more it can / will promote your game in relevant searches! If you don't tag your games, then they can't show up in any search results, but the more tags and metadata you provide for your games, the more opportunities they have to show up in searches.
Lastly, I'd recommend downloading ScreenToGif, one of the greatest programs on the internet, and recording a GIF of your gameplay to use as your game's cover image. This is a really professional move that makes your game standout from the crowd, and again just great practice, especially for someone so young!
Keep up the good work! You'll have a great future in game development if you keep up this pace for your next few years through secondary school.