Game performs less favorably when at double speed

[Simos Xenitellis ]

When running the game at double speed, it performs less favorably than running at the standard speed.
To test:
1. Run the letters variant, at Level 29 (Difficulty: Hard). We are testing the first wave by placing a single tower ($30) at position [8,5].
2. At standard speed, you can safely clear the first stage with that single tower.
3. At double speed, there is a high change that a machine will manage to pass and reach the end.