diff -r f2a19a6056be -r a5ddc6b4abbd share/hedgewars/Data/Missions/Campaign/A_Space_Adventure/global_functions.lua
--- a/share/hedgewars/Data/Missions/Campaign/A_Space_Adventure/global_functions.lua	Mon Sep 25 21:41:38 2017 +0200
+++ b/share/hedgewars/Data/Missions/Campaign/A_Space_Adventure/global_functions.lua	Mon Sep 25 22:25:10 2017 +0200
@@ -124,8 +124,13 @@
 	return checkPoint
 end
 
+-- Reset mission checkpoint to 1
+-- Returns true if the player reached a checkpoint before, false otherwise.
 function resetCheckpoint(mission)
+	local cp = tonumber(GetCampaignVar("CurrentMissionCheckpoint"))
 	SaveCampaignVar("CurrentMissionCheckpoint", 1)
+
+	return (type(cp) == "number" and cp > 1)
 end
 
 function saveCheckpoint(cp)