I really love chess and wanted to make a game which involved chess and cards. At first I thought it was really cool idea but after a quick test the cards made chess feel secondary or basically not needed. It was like a card game with too many rules. I also started to make cards that weren't aligned with pieces (like if I can cast thunderbolt then what's the point of the pieces) and more importantly started to realise that I would much prefer cards aligned with the pieces themselves than someone who just oversees and casts spells.
So I decided to remove cards from the game on the second iteration and instead build health bars on each piece. The levelling would occur on each piece individually and it felt great just moving the pieces alone to hit them.
Migrating the abilities on the player themselves and the enemy
That said, i did end up migrating an ability to the player/enemy themselves in the end to give spice but also so enemies had more interesting mechanics (an example is Brutus who can one shot your king with a pawn one shot but also bring your king forward on his turns - this was my most fun making a mechanic that fit the floors of hell).
Why 6 x 6 and not 8 x 8
This was a tough decision but the more I played the game, the longer it took for me to even finish a battle. It didn't have the speed and didn't have the 'feel' I liked. Plus, the time to engage in combat took ages. In a 6 x 6 grid you force combat faster.
A different way to win, Check and King is not enough
This was my greatest challenge in determining game play. Going for straight king kill ONLY felt really bad. I can't describe it but if thats the only way to win, then the game really just revolves around one strategy: how fast you can glass cannon towards their king. In a small grid this magnified the problem by a lot. So instead, I made the player have health, and that each piece is like your blood. You lose blood based on the piece you lose thus making you die via two methods. "Check" was super interesting for me. I actually got rid of it initially (cause you cant really check a king if the king has health. He can actually 'take' the damage. So I changed this to become a multiplier if a King remains in check.
Happy to answer any questions!
Regards,
Pas