I had lots of fun trying this out! :D It feels like a real gem in the making.
I especially loved the creature designs and I was captivated by the puzzle of trying to win battles with an exact zero - it revived my childhood love of turn-based RPGs, which is no mean feat! (They had lost much of of their appeal to me over the years for tending to get boring due to first-order optimal strategies of just hitting with big numbers, rather than requiring much thinking.)
I'm quite picky about roguelike deckbuilders in general, since the market is packed with many options to choose from, but this one had a strong unique selling point and I really liked the gameplay and the thoughtful card design.
I feel like this could also become an amazing tool for encouraging maths students to practice their mental arithmetic in a way that feels genuinely fun, where the maths is core to the gameplay and not just tacked on to unrelated game elements to try and make homework more appealing.
Some constructive criticisms for you to consider:
- Fonts are uncomfortably small for me (someone without any visual impairments) even when playing on full-screen (the screen I was using is 15.5 inches). This might not be as much of an issue for folk on larger screens, but it could definitely stand to be improved for general UX - either by offering accessibility options to tweak sizing, or just rescaling some of the graphic design elements so that players can have an easier time reading it by default.
- I noticed some negative space going unused for game-relevant content (e.g. background art at the bottom is cute, but I'd rather have larger cards with bigger font that are easier to read), while some written information was simultaneously very cramped/overlapping (e.g. "overkill").
- This is a quite time-consuming game, especially when a player is first getting to grips with all the mechanics. I found myself locking in and wanting to play for quite a while, which is great, but even then I didn't make it to the end of a run before running out of focus (I'm a spoonie with brainfog). So it would be really nice to have an option of downloading it for chance to save progress and play in bursts, instead of browser-based play and the looming threat of losing progress upon exiting the page / clearing cookies. (Apologies if there is such an option and I missed it!)
- Seconding the feedback that it could use some music. While it's admirable that your team want to make original music for it, perhaps you could add some copyright-free or Creative Commons-licenced music options as placeholders in the meantime?
Overall, I'm really hyped to see how this game develops! I'd like to play more of it, but I probably won't attempt to until the accessibility barriers for me personally are resolved - please consider giving me a heads-up if/when that happens, so I can check it out! :D