This is a totally new version of SAP based on 1.20.1 that focuses more on combat and progression. Most prominent changes are:
Movement! You can now slide, air-dive, and wall-run. Slide-jumping also gives a burst of speed, making it the new best way to traverse the world.
Difficulty settings! Each mob now has a set difficulty, irrespective of where or what level you are. This increases per player by 20% for all stats. Lenient deaths are also no more; the death system is just like Vanilla.
Progression! No longer are levels just basic stats, version 5 now uses the Simply Skills progression system.
Ambience! Enjoy tons of new furniture, passive mobs, and structures.
Spells! With Spellblades and Such, enjoy tons of new spellbooks to experiment with.
Dimensions! Now with Mine Cells, and the Mirror dimension from Spellblades and Such.
Trimmed fat! Removed features that were rarely/never used, or were confusing.