Journey to the Savage Planet is a wacky exploration adventure where you must explore an alien world and learn about the unique creatures and vegetation. You have the option to turn it into a cooperative experience, but you can also choose to do it by yourself, too. The game provides you a variety of tasks you need to complete, and eventually, you need to increase your overall rank.
You can find your rank at the top of the screen on your main menu. You should see what level of rank you have, and each rank has a unique name attached to it. The higher of a rank you have, the more experience you have as a seasoned explorer. To increase this rank, you need to focus on completing science experiment missions in your journal.
You can find the science experiments listed in your journal, which you can see by opening up your in-game menu and going to the journal to the left of your character page. These science experiments request you perform specific tasks. You may need to locate particular creatures on the planet to eliminate them in a specific manner, acquiring live samples, or finding materials.
These tasks vary, and they force you to think about different ways to complete a mission. You can track any science experiment by hovering it in your journal and clicking it. You want to complete science experiments and continually rank up so you can unlock new upgrades and items for your journey.