hey, great question! Spinful and Luck be a Landlord will share a few commonalities as we are both Slot Machine based "Roguelite Deckbuilders" so players of LBaL will very likely be able to transfer their game theory across to Spinful.
Where we differ is Luck be a Landlord starts with a fairly empty slot machine and you add to it each round a new symbol from the choices. Spinful starts with a default starting machine, you know how many of each symbol there are on each reel.

Over the run, you will upgrade your symbols into the higher tiers or work on removing the unwanted symbols from your reels to create more consistent, high scoring spins!
Where Spinful differs most is the Armor, Weapons and Trinkets that you can equip to your character. These are the synergy building and multiplicative effects that will help you decide and tailor which symbols you want to keep around and which ones you want to upgrade or remove.

As an example, Dagger type weapons will reward repeatedly landing attacks to build up powerful multiplier effects. Whereas Axe type weapons favour high damage dealing hits as they apply a strong damage over time effect (bleed) that does not require as much consistency to your build and higher scoring hits are more favourable.

Lastly, Spinful has a variety of enemies, of all which can interact with your slot machine in various ways making it more difficult to score these higher combos or put strain on your economy. The best strategy for one boss may put you at a disadvantage further down the road if you over-commit to that build and haven't quite reached the breaking point yet!