A few lines of implementation and I am doubting my resolve.

src/main.c

@@ -0,0 +1,135 @@
+/* Collision groups: */
+/*   0x1 - top and bottom walls */
+/*   0x2 - player */
+/*   0x4 - enemies */
+/*   0x8 - side walls */
+/*   0x10 - bullets */
+
+#include "pd_api.h"
+
+#include "kani.h"
+#include "enemies.h"
+#include "wave.h"
+
+/* local player = nil */
+/* local ui = nil */
+/* local currentWave = nil */
+
+/* function playdate.update() */
+/*    gfx.sprite.update() */
+/*    if currentWave:update() then */
+/*       -- fight forever lol */
+/*       currentWave = newWave() */
+/*       playdate.timer.performAfterDelay(1000, Wave.add, currentWave) */
+/*    end */
+/*    playdate.timer.updateTimers() */
+/* end */
+
+Kani* player = NULL;
+UI* ui = NULL;
+Wave* currentWave = NULL;
+
+int update(void* userdata) {
+  PlaydateAPI* pd = userdata;
+
+  pd->sprite->updateAndDrawSprites();
+
+  if (currentWave->update()) {
+    currentWave = newWave(pd); // TODO: this is a stub that just repeats the same wave over and over
+    currentWave->add();
+  }
+}
+
+int eventHandler(PlaydateAPI* pd, PDSystemEvent event, uint32_t arg) {
+  if (event == kEventInit) {
+    pd->system->setUpdateCallback(update, pd);
+
+    currentWave = newWave(); // TODO: this is a stub that just repeats the same wave over and over
+    currentWave->add();
+
+    ui = newUI(pd);
+    player = newKani(pd);
+  }
+}
+
+Wave* newWave() {
+  
+}
+
+/* function setup() */
+/*    ui = UI() */
+/*    player = Kani(ui) */
+/*    player:moveTo(16, 120) */
+/*    player:add() */
+/*    ui:add() */
+
+/*    makeWalls() */
+/*    drawBackground() */
+/* end */
+
+/* function makeWalls() */
+/*    makeWall(200, 0, 400, 1, 0x1) */
+/*    makeWall(0, 120, 1, 240, 0x8) */
+/*    makeWall(200, 240, 400, 1, 0x1) */
+/*    makeWall(400, 120, 1, 240, 0x8) */
+/* end */
+
+/* function makeWall(x, y, w, h, mask) */
+/*    local wall = gfx.sprite.new() */
+/*    wall:setSize(w, h) */
+/*    wall:setCollideRect(0, 0, wall:getSize()) */
+/*    wall:moveTo(x, y) */
+/*    wall:setGroupMask(mask) */
+/*    wall:add() */
+/* end */
+
+/* function drawBackground() */
+/*    local backgroundImage = gfx.image.new(400, 240, gfx.kColorWhite) */
+/*    gfx.sprite.setBackgroundDrawingCallback( */
+/*       function(x, y, width, height) */
+/*          backgroundImage:draw(0, 0) */
+/*       end */
+/*    ) */
+/* end */
+
+/* -- Right now we only have a single wave and we repeat it forever */
+/* function newWave() */
+/*    wave = Wave.new() */
+
+/*    local startPosition = geom.point.new(410,120) */
+
+/*    local enemy = Ika(player) */
+/*    enemy.introAnimator = gfx.animator.new( */
+/*       5000, */
+/*       startPosition, */
+/*       geom.point.new(350,120) */
+/*    ) */
+
+/*    wave:addEntity(enemy) */
+
+/*    local y = 50 */
+/*    for x=270, 300, 10 do */
+/*       local dir = 1 */
+/*       if math.random(2) == 1 then */
+/*          dir = -1 */
+/*       end */
+/*       local vector = geom.vector2D.new(0, dir) */
+
+/*       enemy = Ebi() */
+/*       enemy.vector = vector */
+/*       enemy.introAnimator = gfx.animator.new( */
+/*          2500, */
+/*          startPosition, */
+/*          geom.point.new(x,y) */
+/*       ) */
+
+/*       wave:addEntity(enemy) */
+
+/*       y += 50 */
+/*    end */
+
+/*    return wave */
+/* end */
+
+
+/* setup() */