How to Fix Tower Defense Waves Spawning All at Once in GameMaker

A wave should trickle out, not dump on the path entrance in one frame. Spacing spawns with a per-enemy timer fixes the pile-up. Here is how in GameMaker.

How to fix it

1. Hold a spawn list

Store the wave as a queue of enemy types with a spawn interval. Do not loop and instance them all in the Create or a single Step event.

2. Release one per interval

Use an alarm or a counting-down timer in the Step event; each time it elapses, spawn the next enemy from the queue and reset the timer until the queue empties.

3. Gate the next wave

Start the following wave only after the current wave's queue is empty and a between-wave delay has passed, so waves do not overlap unexpectedly.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every GameMaker error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.