Thanks for the feedback.
This is only the second game we've added the leaderboard to, but it isn't too hard to implement. It is a free one offered by silentwolf.com . In some previous jams people started using it and mentioned it in the discord, so we gave it a try.
We designed the items and combat with the idea of different types of attack and defense, and needing to use the right ones for the enemy. We didn't have time to implement that, so most things got reduced to just base physical and magical attack/defense. Early on the enemies are mostly no armor, so you're right that there isn't as much need to pick the right item. The main reason for the variety is to let people see the different items and maybe get a feel for them. It will help later when we add more effects so they look different when used. We are rebalancing things for our post-jam update, and will look at the starting loadouts as we do that. We always planned for the number of slots in your belt to be upgraded over time, so maybe we reduce the number you start with and give you the first option to upgrade sooner.
We have more planned for the gameplay loop. There will be more strategy in what items to use based on the element/attack type. Status effects will be added in a future update. The items you eat are also going to affect your stat growth. You may choose to eat an item that does little damage, but gives you a temporary, or permanent, stat buff. Each slime is going to get a special ability... we've got a lot planned.
We try to make all our games playable on keyboard/mouse, controller, and mobile, though don't always succeed. For the jam it often comes down to not enough time to fully test on mobile.
Thanks for playing.