Dream Flash is a rogue-like bullet hell game created by RamafParty. It was recently updated to the 19th demo, which added a new boss, new music, resprites, and made the game easier to mod. As of now, the game has not fully released yet, but the demo is currently available on Steam.
BTDX: What to Play When You Are Bored of 5&6
BTDX is a fan made BTD game made before BTD6 but after BTD5. It features much more content.