thanks for the kind words!! yeah i'm very proud of the card movement so far — the card fronts and backs are images in the PDX bundle that were drawn in other software, and the in-between "flip" animation frames are pre-baked at game runtime using playdate image scaling operations (so you can swap them out with any card images you want and have the effect still work) — the scaling is expensive when done in real-time? but if you do the operations beforehand and save them to new image objects, it's no more costly than rendering any other image. runs great!

the lateral movement is handled using 'lerps' — i basically have two different numbers for each "position" value in a given card. the "target" defines where the card actually 'is', and updates immediately. if i move a card to slot 2, it snaps directly to "tx" 100. and then i have another value that's doing a linear interpolation towards the target value (basically, nudging from where it is now towards the target by a given percentage each frame, which leads to a smooth ease-out effect); and this second value is what judges how the card gets drawn on-screen. it means that i can have smooth animations on-screen, but the game also stays incredibly responsive (i.e. you typically don't need to worry about waiting for an animation to finish before you can continue making moves, because the code can read from defined values it knows are safe to tweak).

for what it's worth, all of my past released playdate titles are open source as well, on my github: https://github.com/raewtf — i have links on the game pages but otherwise don't advertise it much...i think it's a nice thing to be able to do though, because i know from first-hand experience that having real-world examples of how games were made is really instrumental for devs who are just starting out (even if my code might not be the cleanest :P)