Hi! Thank you so much for your feedback. We glad you enjoyed our game.
About the issues.
- The chest can be open by using "punch" ability (east button on the gamepad or Left Ctrl on the keyboard by default).
- You should be able to switch to any form you obtained earlier by using radial menu (Left Stick or Left Alt by default). You can also switch to the previous form by pressing RB on the gamepad or Tab on the keyboard. Unless there is actually a bug we've never encountered before
- There is an item near fire slimes which gives you the fire form. This form allows you to burn flammable objects like dried thorns, wooden doors and barricades.
Please let us know if these tips helped or not.
We also planning to release patches every week so stay tuned!