One thing I had a very hard time with as a kid, and no internet to use as reference, was xp, damage, and health curves. How do you make sure the player doesn't get over powered too quickly? Or enemies don't one shot you if you after a few levels? Luckily with the internet now you can easily just look up great formulas for these. Today I made a table showing roughly what these values will be over a set of levels. After testing this out a bit I'm pretty happy with the values. I thought I'd share my super easy formula here:
Basically this gives me a gentle curve up of xp needed to hit each level. I did the same with different exponents for damage, enemy damage, enemy hp, player hp, armor, etc. All the things. The player stats change based on their level, the enemies change based on the stage. Which is important because it gives the player room to get stronger than enemies if they roam to kill them all. If you skip a lot you'll also end up feeling a bit under powered. Which is ideal. Enemies leveling with you is never fun because numbers go up but difficulty remains flat. Boring!
In art news I started making some mine cart rail tiles because who doesn't like mines?