Complex sentence: The quests are relatively simple to complete (other than the secret areas and the retro dungeons, which are not essential to the game) and the game gives you a journal, with highlighted items indicating things that warrant further investigation.
Split into simpler sentences: The quests are relatively simple to complete (other than the secret areas and the retro dungeons, which are not essential to the game). The game provides a journal system, with highlighted items indicating things that warrant further investigation.