diff --git a/SpaceCadetPinball/TPlunger.cpp b/SpaceCadetPinball/TPlunger.cpp
index dcbf324..7e373fa 100644
--- a/SpaceCadetPinball/TPlunger.cpp
+++ b/SpaceCadetPinball/TPlunger.cpp
@@ -37,7 +37,7 @@ void TPlunger::Collision(TBall* ball, vector_type* nextPosition, vector_type* di
 {
 	if (PinballTable->TiltLockFlag)
 		Message(1017, 0.0);
-	coef = RandFloat() * Boost * 0.1f + Boost;
+	coef = RandFloat() * Boost * 0.1f + Boost; //!! passed in coef is never used
 	maths::basic_collision(ball, nextPosition, direction, Elasticity, Smoothness, Threshold, coef);
 }
 
@@ -109,7 +109,7 @@ int TPlunger::Message(int code, float value)
 			if (PullbackTimer_)
 				timer::kill(PullbackTimer_);
 			PullbackTimer_ = 0;
-			if (code == 1005)
+			if (code == 1005) //!!
 				loader::play_sound(SoundIndexP2);
 			auto bmp = ListBitmap->at(0);
 			auto zMap = ListZMap->at(0);
diff --git a/SpaceCadetPinball/control.cpp b/SpaceCadetPinball/control.cpp
index 5e401bb..98684f2 100644
--- a/SpaceCadetPinball/control.cpp
+++ b/SpaceCadetPinball/control.cpp
@@ -1019,7 +1019,7 @@ void control::LaunchRampControl(int code, TPinballComponent* caller)
 			{
 				sound = control_soundwave21_tag.Component;
 			}
-			else if (someFlag <= 1 || someFlag > 3)
+			else if (someFlag <= 1 || someFlag > 3) //!! <1 ?
 			{
 				sound = control_soundwave24_tag.Component;
 			}
@@ -2148,7 +2148,7 @@ void control::HyperspaceKickOutControl(int code, TPinballComponent* caller)
 		}
 		else
 		{
-			if (someFlag <= 1 || someFlag > 3)
+			if (someFlag <= 1 || someFlag > 3) //!! <1 ?
 			{
 				auto duration = control_soundwave41_tag.Component->Play();
 				control_soundwave36_1_tag.Component->Play();
@@ -2919,7 +2919,7 @@ void control::GameoverController(int code, TPinballComponent* caller)
 
 	if (missionMsg & 0x200)
 	{
-		int highscoreId = missionMsg % 4;
+		int highscoreId = missionMsg % 4; //!! %5 ?
 		int highScore = pb::highscore_table[highscoreId].Score;
 		auto nextHidhscoreId = highscoreId + 1;
 		if (highScore > 0)
@@ -3923,9 +3923,7 @@ void control::SelectMissionController(int code, TPinballComponent* caller)
 			if (light_on(&control_lite319_tag))
 				control_lite319_tag.Component->Message(20, 0.0);
 			if (!light_on(&control_lite317_tag))
-			{
 				control_lite317_tag.Component->Message(7, 0.0);
-			}
 		}
 		else
 		{
@@ -4158,6 +4156,7 @@ void control::TimeWarpPartTwoController(int code, TPinballComponent* caller)
 	control_lite317_tag.Component->Message(20, 0.0);
 	control_lite198_tag.Component->MessageField = 1;
 	MissionControl(66, nullptr);
+	//!! Display score?
 }
 
 void control::UnselectMissionController(int code, TPinballComponent* caller)
diff --git a/SpaceCadetPinball/fullscrn.cpp b/SpaceCadetPinball/fullscrn.cpp
index fa838c3..f26d049 100644
--- a/SpaceCadetPinball/fullscrn.cpp
+++ b/SpaceCadetPinball/fullscrn.cpp
@@ -58,7 +58,7 @@ int fullscrn::enableFullscreen()
 	if (!display_changed)
 	{
 		SDL_SetWindowFullscreen(winmain::MainWindow, SDL_WINDOW_FULLSCREEN_DESKTOP);
-		display_changed = 1;
+		display_changed = 1; //!!
 		if (display_changed)
 			return 1;
 	}
diff --git a/SpaceCadetPinball/midi.cpp b/SpaceCadetPinball/midi.cpp
index 68a19a1..db428c0 100644
--- a/SpaceCadetPinball/midi.cpp
+++ b/SpaceCadetPinball/midi.cpp
@@ -318,5 +318,5 @@ std::vector<uint8_t>* midi::MdsToMidi(std::string file)
 	delete[] fileBuf;
 	if (returnCode && midiOut)
 		delete midiOut;
-	return midiOut;
+	return midiOut; //!! could be already deleted
 }
diff --git a/SpaceCadetPinball/winmain.cpp b/SpaceCadetPinball/winmain.cpp
index cef4dbe..bdcaa1b 100644
--- a/SpaceCadetPinball/winmain.cpp
+++ b/SpaceCadetPinball/winmain.cpp
@@ -19,7 +19,7 @@ int winmain::bQuit = 0;
 int winmain::activated;
 int winmain::DispFrameRate = 0;
 int winmain::DispGRhistory = 0;
-int winmain::single_step = 0;
+int winmain::single_step = 0; //!! is constant
 int winmain::has_focus = 1;
 int winmain::last_mouse_x;
 int winmain::last_mouse_y;
@@ -180,7 +180,7 @@ int winmain::WinMain(LPCSTR lpCmdLine)
 			if (!gfr_display)
 			{
 				auto plt = static_cast<ColorRgba*>(malloc(1024u));
-				auto pltPtr = &plt[10];
+				auto pltPtr = &plt[10]; // first 10 entries are system colors hardcoded in display_palette()
 				for (int i1 = 0, i2 = 0; i1 < 256 - 10; ++i1, i2 += 8)
 				{
 					unsigned char blue = i2, redGreen = i2;
@@ -215,8 +215,8 @@ int winmain::WinMain(LPCSTR lpCmdLine)
 				int x, y, w, h;
 				SDL_GetMouseState(&x, &y);
 				SDL_GetWindowSize(window, &w, &h);
-				float dx = (last_mouse_x - x) / static_cast<float>(w);
-				float dy = (y - last_mouse_y) / static_cast<float>(h);
+				float dx = static_cast<float>(last_mouse_x - x) / static_cast<float>(w);
+				float dy = static_cast<float>(y - last_mouse_y) / static_cast<float>(h);
 				pb::ballset(dx, dy);
 
 				SDL_WarpMouseInWindow(window, last_mouse_x, last_mouse_y);