The obsidian Modpack is a pack of carefully picked and configured mods inspired by Vanilla Minecraft and over 5 years of play experience and crushed dreams. The pack is generally more difficult in terms of survival and combat, supports long-lasting gameplay (even on servers), and has meaningful early-game progression.

One of the game-changing mechanics in the pack is using the Crafting Station from BetterStorage to add recipes which require experience to craft. Not to mention getting it in the first place is a bit of a challenge, requiring you to get gold and redstone in some way, or skipping everything by finding the required tools through exploration.

Tons of recipes are changed to fit the modpack and integrate the mods with each other. A good example is Flaxbeard's Steam Power, with some items completely removed from the game, others more difficult to craft, and lots of it integrated with Vanilla and the other mods. By the way, did you know Flaxbeard's has guns?

This modpack is experimental and most likely won't ever be truly finished. You can check out the GitHub page to find out more, check on development progress, join discussions, or even help with the project!
I encourage you to try out the included resource pack. It changes the hotbar and some icons, as well as a few blocks and items to make things a little more consistent.