A few tips:
- You can get iron bars from smelting iron ore in a furnace.
- Swords are very damaging compared to spears, but spears have a longer range.
- dropping raw food (meat, shrimp, ect) in a lava pool will cook the entire batch in seconds, however may "burn" and disappear if left too long
- Shields considerably protect you if you are running away.
- The red demon-boss can be trapped by a single spike wall and adamant ore node if placed correctly, allowing you to damage him with melee weaponry without getting hit (but I think swords may be too short for this).
- You can jump with space. This is a must for running away from high level players.
- If you time it right, you can preform a jump-slash with melee weaponry which can deal over three times its normal damage. (Not checked with all weapon types)