Merge Objects using Checkpoints!
I've discovered a new glitch! It allows you to merge objects even with grid mode, but without all the hassle of setting up emitters. :) The only drawback is that for it to work there can't be any checkpoints already in the level.
1. If there are already any checkpoints in the level, delete them. (If there's only one, duplicate it and delete both at once.) Also make sure you are in Pause Mode.
2. Get the object you want to merge, and place a checkpoint a small distance away from it.
3. Capture both the object and the checkpoint at once.
4. Delete both the object and the checkpoint.
5. Select the object from the My Objects page, but DON'T PLACE IT YET! Instead, move it over to where you want to merge it.
6. Press the Cancel button. The game will place the object regardless, even if it means overlapping it with another object!
7. Glue the two objects together so that they don't break in Play Mode.