The alpha version excludes original cinematic sequences to save space.
The engine runs on the GBA's stock 16.78MHz ARM CPU. While the frame rate is relatively low (roughly 16fps), it features textured polygons and Gouraud shading.
The GBA has a 16.8 MHz ARM7TDMI CPU and 32KB of RAM. For context, the original Tomb Raider PC required a 60 MHz Pentium and 8MB of RAM. So, how does OpenLara manage this?
Technical Assessment and Feasibility Report: OpenLara on Game Boy Advance (GBA)