Frontier Bastion

Cinevva's analyzer read this game's design doc and its source, then wrote the brief below. "Make your own" hands it to the game creator as your opening message, so you start from a real spec rather than a one-line idea.

Create a responsive single-screen 2D top-down tower-defense game titled “Frontier Bastion.” Use a dark navy sci-fi UI and a canvas playfield centered in a narrow desktop/mobile-friendly layout. The page has a dark #101827 background, a top header labeled Frontier Bastion, and stats showing Gold, Base, Wave, and Score. Below it is a large rounded-rectangle battlefield with a subtle dark-blue square grid, plus an instructional overlay at the upper left: “Pick a tower, then tap a pad. Survive each wave and upgrade between fights.” Under the battlefield is a control bar with tower selection buttons, a wave-start button, an upgrade button, and a small status message.

Gameplay is a lane-based tower defense viewed from directly overhead. Enemies enter from the left edge and follow one fixed thick, winding road across the field: travel right, turn upward, travel right, turn downward, travel right, turn upward, then exit through the right edge. Draw the road as a rounded dark slate-blue track with a lighter outer border. Place eight circular build pads away from the road at approximately normalized positions (10%,72%), (29%,38%), (36%,86%), (55%,38%), (62%,18%), (80%,62%), (87%,20%), and (82%,86%). Pads are dark blue circles with lighter outlines.

The player begins with 120 gold, 20 base/lives, wave 0, and score 0, in a build phase. Select one of two tower types, then tap/click a vacant pad to build it. The default selected tower is the Blaster, costing 50 gold; the Cannon costs 80 gold. Prevent building during an active wave, on non-pad locations, or on occupied pads, and show brief centered toast messages for invalid placement or insufficient funds. Towers are square sci-fi turrets: a dark base with a colored inner square and a short white barrel that rotates toward its target. Blasters are cyan, have range 118 pixels, fire every 0.42 seconds, and deal 13 damage. Cannons are orange, have range 145 pixels, fire every 0.82 seconds, deal 27 damage, and have 35-pixel splash damage that applies 45% of the shot damage to nearby enemies. Show a faint colored circle for each tower’s attack range. Show a gold selection ring around the selected tower and gold star markers above it indicating level (one to three stars).

Starting a wave changes to wave phase and clears tower selection. Wave 1 starts with 6 plus three times the wave number enemies, and every wave spawns additional enemies; spawn roughly every 0.85 seconds, with the interval gradually shortening by wave but never below 0.28 seconds. Enemies move along the road toward the right exit. Normal enemies are pink/red circles with 30 + 12 times the wave number max HP, speed 34 + 2 times the wave number, and reward 10 + wave gold and score. Some enemies become fast variants (up to 28% chance at later waves), colored coral/orange, with 1.45x movement speed. When an enemy reaches the end, remove it and reduce Base by 1; a fast enemy also costs 1 base. Display a small HP bar above every enemy, with green fill for normal/fast enemies. Towers automatically target the enemy furthest along the road within range. Render short colored beam/tracer shots from tower to target; after the short projectile lifetime, apply damage. Remove defeated enemies, award gold and score, and update the HUD.

Every fifth wave is a boss wave. Include one boss in the spawn count, clearly announce it with a centered toast such as “Boss wave 5 — prepare your defenses,” and identify the wave in the status line as “BOSS WAVE [number].” The boss is a larger purple circle with a gold outline, 240 + 40 times the wave number HP, speed 22, a larger HP bar, and reward/score of 100 + 10 times the wave number. A boss reaching the exit reduces Base by 3. Normal waves and boss waves end only when all scheduled enemies have spawned and all enemies are defeated or have exited. On clearing a wave, return to build phase and award bonus gold of 25 + 6 times the wave number, with a toast such as “Wave 1 cleared — bonus gold awarded.”

During build phase, allow the selected tower to be upgraded through the “Upgrade selected” button, but only if a tower is selected, it is below level 3, and enough gold is available. Upgrade cost starts at the tower’s original cost and increases by multiplying by 1.45 and flooring. Each level increases damage by a multiplier of 1 + 0.55 times (level - 1), while preserving the tower’s type/range/rate. Disable upgrade during waves, with no selection, at level 3, or when unaffordable. The start button should say “Start wave 1” initially and then “Start wave N,” and be disabled during waves. The status text should communicate build phase, tower count, wave enemy count, boss-wave state, or defeat state.

If Base reaches zero, stop active wave play, show a dark translucent overlay over the battlefield reading “Bastion Lost” and “Tap Start to rebuild and try again,” and make the Start button function as restart: restore 120 gold, 20 base, score 0, wave 0, build phase, and remove all towers, enemies, and shots. Make the canvas resize to its container, support pointer/touch input, and keep controls usable on small screens. Use clean flat vector/canvas shapes, rounded UI panels, cyan/orange/pink/purple/gold accents, subtle grid lines, and no external assets.