4 in 1 Fortress Frenzy is 09dhowell's 400th level on pouetpu-games. It is a special level made up of four separate levels and is x12000 long overall. The player has a choice of which level to play at the start, and each level is a different theme and difficulty, in order from easy to extreme. Link to level
The level currently has over 70 votes and an average of 99%, with very positive reviews from everyone who rated it.
Level critic scores:
Lord Apoplexy: 10/10