I'm glad I got to play this game. It was charming in a Studio Ghibli kind of way -- a rare delight in the world of free print-and-play games.
Your mechanics do a nice job of dangling the player over the precipice of defeat before yanking them back with what feels like a clutch play. Your rules are simple and effective, with enough wiggle room for players to develop their own strategy.
The best part, though, was undoubtedly the campaign. Nine of the ten opponents were well thought out and interesting in a Slay the Spire kind of way. The arc of your story, the description of the enemies, and the way they matched the mechanics were excellent.
A few things I would take a look at.
- Spelling and grammar! Proofread your work, and then have someone else proofread it, too. You'd be amazed how easily the wrong word can pull the reader out of a story.
- The Flea Soldiers. The story and the idea is incredibly cute. Actually fighting them was an exercise in frustration. It's not that they were difficult -- it was that missing completely on five out of six rolls makes the player feel like they are incapable of making progress. Or at least makes me feel that way, and I assume others do, too. It also risks turning the best part of the game into busywork, as the player will generally have almost nothing to heal. Try something for me: fight the Flea Soldiers as you have them now, and then try them with 25 health, and with the following rule in place of only hitting on doubles: "Little Warrior's damage is reduced to 1 per die, unless he rolls doubles". See which one feels better. It might just be me, but being able to make at least a little progress each turn feels better than making no progress at all most turns.
- I might see what other effects I could tie to certain poker hands, or shuffle around the ones that are already there. For example, I found straights to be surprisingly hard to get (much harder than flushes) and relatively lackluster compared to other options. Again, this might just be me and the way I play.
- Finally, I would name the spells and give them some flavor text. You obviously have a talent for game narrative, and it was odd that you didn't apply this strength to your game's mechanical centerpiece. It's cool that a flush gives me three turns without damage, but you haven't shown me why it works that way in the narrative. Am I creating floating shields? Mirror images of Little Warrior that draw fire? Fireflies that dazzle the opponent so they can't see to attack?