@Sgtpenguisbackbaby! Here is my advice:
-Add details to your level. Just explaining the look makes the level shorter. You can add much more details, logs, and survival tips. That is what makes your level longer.
-Use creativity, not just recolor level 0. More creativity means more details also.
-Use wikitext. The more wikitext you use, the cooler the page looks. However, dont use it randomly and not too much.