Floppy Knights isn't a terrible game by any stretch of the imagination. There was obvious care put into it, it has clean stylized visuals, a serviceable plot, a and a pleasant soundtrack to tie it all together. But for me it really falls flat in the most important area, the gameplay.
It's certainly a unique system, and Floppy Knights deserves some credit for being willing to try an innovate on the genre, but just because a system is innovative doesn't make it good. It's for the most part a fairly basic 2d grid based tactics game, with units having only 3 core stats (Health, Move, and Attack), and enemies getting one move and attack action per turn. But the big "twist" of the game is that all your units do not get a free movement action each turn and instead have to rely on your cards to move around. This is an odd design choice, as you always get the same 5 or so actions per turn, regardless of how you want to spread them across your units. Maybe this was put in place to prevent players from snowballing and spamming units to beat the enemy by sheer numbers, but it causes the exact opposite problem, as there really isn't any reason to deploy more than 1-2 units for any map. This leads to a majority of maps where you just send you one guy to complete all the objectives, and I'm genuinely unsure if this is the intended playstyle or not.
Another issue is that of the loss condition. For most maps, the only way to lose is if you get you commander killed, so you are encouraged to just hide them in the back while you send your summons to do everything for you. This is further worsened by the fact that summons are sent back to your deck on kill, meaning that if you turtle like that there really isn't any risk of losing as you can just re-summon the unit and send it back out there at no real negative impact. You have to pay for the summon again, and getting it killed adds a 1 cost trash card to your deck so there is a small consequence for your units death, but it only amounts to a minor inconvenience at worst and can be completely resolved in a single turn. If anything, getting your units killed can even sometimes be a good thing, as re-summoning your unit gives another copy of its correspondent spell cards, which can be worth the sacrifice dependent on the unit.
Also there is the matter of timed objectives. Throughout most of the game, there is no incentive to go fast, or to push forward at all other than to just beat the level, further reinforcing the turtling strategy mentioned prior. The only real counter measure is that almost all maps have infinitely spawning reinforcements, which doesn't make the game harder as much as it just makes it a slog. If both sides have unlimited resources to throw at each other then there isn't much strategic value to any of the resources, so you can get by just flinging the same unit at the enemy until you come on top. This means that the battles are far more a test of patience than of actual strategy or tactics, as battles can be won with just brute force and time. However, this is the only other mechanic in the game that incentivizes deploying more units, as your units can block the re-spawn points. So extra deployments do a have a use, to just sit there and do nothing, blocking the re-spawns while your one guy actually does stuff to complete the objective to beat the map.
Additionally, there is the issue of card balance, which is extremely all over the place. There's one card which is free, draws a card on play, and gives an extra energy next turn. This card is literally just free econ, there is never any reason to not have it in your deck. It's not game changing in its strength, but there is no opportunity cost for using it so it's a must pick in every deck. Most other cards aren't as questionably designed, but there's a fair few cards that are just strictly better/worse versions of existing cards.
Furthermore, having all your actions be randomly drawn from a deck makes the entire game really luck based, as your turn is entirely dependent upon what you draw. Yes, ideally your deck should have a good split of movement and attack cards, but there is nothing stopping you from just getting unlucky and drawing a handful of one when you needed the other. However, there is at least always one guaranteed movement card that you get from your champion, but that isn't enough to offset the complete RNG from the rest of your hand. This is especially the case for the upgrade cards, which are free one time use cards that upgrade another card in you hand for the rest of the fight. What other cards you draw determines what you can upgrade, which has significant lasting consequences for the rest of the battle.
All these issues are compounded with the fact that this game is slow, to the point where it feels like the game just doesn't respect your time. All animations, from moving to attacking to drawing your cards are really slow, and the only one with the option to be sped is the walking speed, but that is only up to x2 and honestly that feels like what the speed should've been at to begin with.
Overall, while this game does have many redeeming qualities, every-time I came away from the game I just ended up feeling annoyed, to the point where I just gave up on playing it. It makes me a little sad because I wanted to like it (obviously nobody buys a game wanting to dislike it) but there is so much that I fundamentally dislike about this game that it would have to be entirely reworked for me to recommend.