This might be cool, as mamy TDs have traps. Could balance out that new armor system. Drop system separated from towers, so might drop as one tower and one trap, but making traps drop with like 1-10% scale. Texture could be something like Skyrims Fire Rune - Destruction Magic, so it won't disrupt the path. Permanent or x-times usable? DoT? AoE, like Bear Hunter? Bear Hunter's traps destroy these traps or unable to place in BH traps or vice versa?
Love the Slate system of GemTD, I could see slates/traps working in MazeBert, but I'm not entirely sure if it could actually be coded.