Yeah, I agree that some descriptions may be unclear. Most cards provide their bonuses passively every day after you buy them, with the exception of the Field and Fortress cards, which only work once when activated. The character does not actually need to walk onto those tiles — they grant their effects passively each day.
The colors of the equipment do matter. Different rarity colors affect both the number of stats an item can have and the quality of those stats (you can check which stats items provide in the left dropdown menu). Equipment is replaced automatically if the new item has better overall stats than the currently equipped one.
For the most part, success depends on how quickly you buy cards, because the game difficulty scales with the number of days passed, while buying cards does not increase difficulty directly — it only increases the boss progress bar. Character stats are also affected by the character level, which increases from gaining resources, killing enemies, and most importantly from buying cards that grant experience. A high level can help compensate for bad luck with equipment drops.
The Lighthouse card activates the effects of several random cards when built (it generates chunks of those cards around itself). Sometimes you might get unlucky and it will spawn a couple of villages or sawmills, but sometimes you can get lucky and the Lighthouse will generate a Dragon Lair, which is much more expensive and gives a chance to obtain very powerful equipment every day.
Thank you very much for the feedback! I’ll definitely keep your experience in mind while developing the full version, and I’ll think carefully about how to solve the gameplay clarity and intuitiveness issues